(Philippine legal context; general information, not legal advice.)

1) The starting point: “Separated” usually still means “married”

In the Philippines, many couples “separate” informally (move out, split finances, stop living together). Legally, that is de facto separation—and it does not end the marriage.

That single fact drives almost everything:

If you are still legally married, a “new relationship” can trigger criminal exposure, family law consequences, and sometimes civil liability, even if you’ve been living apart for years.
Only specific legal events change that status:
- Declaration of nullity (void marriage) or annulment (voidable marriage) with final judgment
- Death of a spouse
- Valid divorce for certain persons (e.g., Muslims under PD 1083; and recognition of a foreign divorce in appropriate cases)
- Legal separation exists, but it does not dissolve the marriage (it only authorizes separate living and addresses property/relations).

So, when people ask “Can I sue my spouse for having a new partner after we separated?”, the legal answer begins with: Were you still legally married at the time? Most of the time: yes.

2) Criminal cases: adultery and concubinage still apply after separation

A. Adultery (Revised Penal Code)

Who is liable:

The married woman who has sexual intercourse with a man not her husband
The man who has intercourse with her, knowing she is married

Key points for “after separation”:

Separation is not a defense. If the marriage still exists, adultery can still be filed.
It is typically tied to sexual intercourse; mere dating, messages, or being seen together is usually not enough by itself, but can be evidence.

Who can file:

Generally, the offended spouse (the husband, in classic framing of adultery) is the complainant; criminal prosecution rules require the offended party to initiate.

Practical realities:

Cases often rise or fall on proof, credibility, and how evidence is gathered.
Illegally obtained evidence (e.g., unlawful wiretapping, hacking) can backfire.

B. Concubinage (Revised Penal Code)

Who is liable:

The married man under any of these common modes:
1. Keeping a mistress in the conjugal dwelling, or
2. Having sexual intercourse under scandalous circumstances, or
3. Cohabiting with a mistress in another place
The mistress may also be liable, depending on the mode alleged.

Key points for “after separation”:

Again, separation is not a defense if the marriage still exists.
Concubinage is not simply “he cheated.” The law requires specific circumstances (dwelling/scandal/cohabitation), which often makes it harder to prove than adultery.

C. Timing, forgiveness, and litigation risk

In both adultery and concubinage:

Condonation (forgiveness) and consent/connivance can be relevant in practice and may weaken or defeat claims depending on facts.
Publicly “allowing” or acknowledging the relationship, or bargaining it away in a settlement, can create complications.
Threatening criminal charges to extort money can expose a party to counterclaims or criminal complaints.

3) VAWC: infidelity can be prosecuted as psychological violence (RA 9262) in some fact patterns

RA 9262 (Violence Against Women and Their Children) covers physical, sexual, psychological, and economic abuse committed by a person who is or was in a dating or marital relationship with the woman.

A. Why this matters for “new relationships”

A spouse’s infidelity may be used as part of a case for psychological violence if it causes mental or emotional suffering and is tied to abusive conduct (humiliation, threats, manipulation, abandonment with cruelty, intimidation, etc.).

Important boundaries:

Not every affair automatically equals VAWC. Courts look at conduct and impact, not just moral wrongdoing.
Evidence often focuses on patterns: harassment, public shaming, threats, coercive control, abandonment without support, and documented emotional distress.

B. Key features of VAWC cases

It can lead to protection orders (Barangay Protection Order / Temporary / Permanent Protection Orders), which can include stay-away orders, support, custody provisions, and restrictions on contact.
VAWC is frequently used when there’s ongoing harassment, economic abuse, or threats, alongside the new relationship.

4) Family law actions that are effectively “suing” (even if not framed as damages)

Even when you don’t pursue criminal cases, the law provides family-law remedies that people use to protect finances, children, and living arrangements.

A. Legal separation (Family Code)

Legal separation allows spouses to live separately and addresses property relations, but does not end the marriage. Grounds include sexual infidelity.

Key consequences:

Potential forfeiture of the offending spouse’s share in certain property regimes (depending on facts and property relations)
Disqualification from inheritance in certain contexts and other marital consequences

Timing constraints commonly exist in practice (e.g., filing within a set period from the cause; “cooling-off” periods), so delay matters.

B. Annulment / declaration of nullity

If granted and final, this changes everything:

After finality, the parties are no longer bound as spouses, so adultery/concubinage tied to that marriage typically no longer applies going forward.
But relationships before finality may still have consequences while the marriage was legally in force.

C. Support and property protection

Even if separated:

A spouse (and children) may sue for support.
There are remedies to protect conjugal/community property if one spouse is dissipating assets to benefit a new partner.
Courts can restrain disposal of property in appropriate proceedings, and financial records can become central.

D. Child custody and parenting arrangements

A new relationship is not automatically disqualifying, but it can matter if it affects:

Child safety
Stability
Exposure to conflict/violence
Neglect, abandonment, or harmful living conditions

Courts apply the best interests of the child standard, not moral judgments alone—though facts sometimes overlap.

5) Civil damages: can you sue the spouse or the new partner for money?

This is where expectations often clash with reality.

A. Against your spouse

You may pursue civil damages under general Civil Code principles (abuse of rights, acts contrary to morals/good customs/public policy, etc.) depending on the specific wrongful conduct—especially where there is:

Public humiliation
Harassment
Fraudulent dissipation of property
Threats, coercion, stalking
Economic abuse or deprivation of support
Violations of privacy or dignity

But Philippine courts are generally cautious about turning “marital cheating” alone into a payday without additional wrongful acts.

B. Against the third party (the new partner)

Philippine law does not have a clean, automatic “alienation of affection” or “homewrecker damages” claim like some other jurisdictions historically did.

Suits against the third party can be possible only when you can anchor liability on an independent wrongful act, such as:

Fraud or conspiracy to hide/transfer assets
Defamation or public shaming
Harassment, threats, intimidation
Acts that violate privacy or cause demonstrable injury beyond the affair itself

If the complaint is essentially “you stole my spouse,” that is usually a weak civil theory on its own. If it’s “you helped loot marital assets” or “you harassed me and destroyed my reputation,” that’s a different case.

C. Strategic note: criminal + civil

Criminal complaints (adultery/concubinage/VAWC) can be paired with civil liability, but the strategy must be handled carefully because:

Evidence standards differ
Settlement dynamics differ
False accusations can trigger counter-suits

6) The “separated but still legally married” trap: children and legitimacy rules

A new relationship after separation can create complex issues for children born during the marriage.

General family-law consequences to be aware of:

A child conceived or born during a valid marriage is often treated as presumptively legitimate under Philippine rules, even if the spouses are separated, unless successfully rebutted through proper legal procedures.
This can affect:
- The child’s status
- Surnames
- Support obligations
- Inheritance rights
- Future custody disputes

Because these issues can permanently affect a child’s legal identity, they’re among the highest-stakes parts of “new relationship” disputes.

7) Common scenarios and what legal actions typically fit

Scenario 1: De facto separation only (no court decree), spouse starts cohabiting with a new partner

Possible actions:

Concubinage (if husband and facts fit dwelling/scandal/cohabitation) or adultery (if wife and intercourse provable)
VAWC (if the wife suffers psychological/economic abuse tied to the conduct)
Support and property protection actions
Custody/visitation cases if children are involved

Scenario 2: There is a decree of legal separation, then one spouse starts a new relationship

Key point:

Still married. Adultery/concubinage risks can remain because legal separation does not dissolve the marriage.

Other effects:

Property regime consequences may already be addressed by the decree, but support/custody disputes can continue.

Scenario 3: Annulment/nullity case is pending, spouse starts a new relationship

Key point:

Still married until final judgment. Exposure can exist for conduct before the final decree.

Scenario 4: Final annulment/nullity judgment already issued

Key point:

New relationships after finality are generally no longer “extramarital” as to that marriage.
But disputes may remain re: property, children, support, contempt of orders, etc.

Scenario 5: A foreign divorce exists (or Muslim divorce), with recognition issues

Key point:

Legal effects can depend on whether the divorce is recognized in the Philippines and the party’s circumstances.
This is highly fact-specific and often litigated.

8) Evidence, privacy, and “don’t commit a crime to prove a crime”

People frequently sabotage their own cases by gathering evidence unlawfully.

High-risk evidence collection includes:

Recording private conversations without consent (wiretapping issues)
Hacking accounts, impersonation, illegal access to devices
Posting accusations online (defamation risk)

Safer, more typical evidence sources include:

Public posts (properly preserved)
Witness testimony (neighbors, building staff, etc., if credible)
Documentary proof of cohabitation/expenses (leases, bills, transfers) obtained lawfully
Child-related records (school, medical) if relevant and legally accessible

9) Defenses and counterclaims to anticipate

If you sue, expect the other side to respond with common lines such as:

“We were already separated” (often morally persuasive, legally weak for adultery/concubinage)
“No intercourse / no cohabitation / not scandalous” (fact-based defenses)
“You consented / forgave” (context matters)
“This is harassment/extortion” (especially if threats were made)
“Defamation” (if accusations were publicized)
“VAWC counter-allegations” (if conduct turns coercive)

10) Practical decision guide: what claim fits what goal?

If your goal is…

Accountability/punishment:

Adultery / concubinage (fact-proof heavy; slow; stressful)

Immediate protection (stop harassment, get support, stabilize children):

VAWC protection orders (where applicable), support, custody-related relief

Financial protection (assets being diverted to the new partner):

Property and support actions, injunction-type relief within proper proceedings

Clean legal reset (ability to remarry, end marital tie):

Annulment/nullity (and related property/child orders)

Often, people file criminal cases expecting quick leverage, but family-law remedies are frequently more effective for day-to-day stability—especially with children and money.

11) Bottom line rules you can rely on

If you are still legally married, a new relationship can still have legal consequences even after long separation.
Legal separation is not “divorce.” You remain married.
Adultery/concubinage depend on specific legal elements—not just “cheating.”
VAWC may apply when the new relationship is part of abusive conduct causing psychological or economic harm.
Civil damages against the third party are not automatic and usually require an independent wrongful act beyond the affair itself.
Children and property issues are usually the most practically urgent and often determine the best legal strategy.

12) If you want to map your situation to the strongest legal options

Use this checklist (for your own analysis before talking to counsel):

Are you still legally married (no final annulment/nullity/divorce recognition)?
Is there evidence of sexual intercourse, cohabitation, or scandalous circumstances?
Are there children, and where are they living now?
Is there economic abuse (withholding support, draining accounts, selling assets)?
Is there harassment or humiliation (messages, threats, stalking, public shaming)?
Are there existing court orders being violated?
What is your priority: protection, support, assets, custody stability, or ending the marriage?

If you tell me the exact status of the marriage (de facto separation vs legal separation vs pending vs final nullity/annulment vs foreign divorce situation) and what the “new relationship” looks like (dating vs living together vs public cohabitation vs harassment/support issues), I can lay out which causes of action are typically strongest and what each one must prove under Philippine practice.