My SIL Demanded Proof My Daughter Was Mine—My Reply Ended the Family Dinner

One Reddit user thought the drama was over when his brother married his mistress. The family tried to act normally until she told him he deserved a paternity test. This exposed the truth that others were too scared to face. Let’s see if that mistress was really on the wrong side.

My brother had an extramarital affair. He divorced his wife and got married to his mistress. Our family is trying to accept her because of my brother.
This Sunday, she said to my wife that it would be nice if she took a paternity test to prove it to “our” family that the child is mine. She said that my daughter could’ve inherited me and had to be a little “fair” as in skin. My wife couldn’t say anything because of sudden shock, but I told her that my wife doesn’t need to prove anything.

She said that it’s best that I find out about my heritage than after, I said she’s a mistress, so she is maybe experienced or inexperienced. My mom pulled me aside and asked, “Why would I say that out loud in front of everyone?” I said with my loud voice that a second-rate mistress is questioning my wife, and she should not be having an affair with married men.

I left with my wife, and my brother asked me and my wife to apologise to his wife. I said I will never apologise to anyone, and I won’t let my wife do so even if she wants to. He said he didn’t want to stay with someone (his ex) because of an arranged marriage, and I replied that I don’t care. His wife is still a mistress, and it’s really weird to ask other women for paternity

My family is broken. In fact, we broke off because of that mistress, but I will never apologise to her or my brother for her accusations towards my wife. Was I wrong?

The internet reacted with fire. And we add some facts.

• The absolute gall of cheaters to accuse others of their same behavior never ceases to amaze me. © ScarletteMayWest / Reddit

• As a mistress, you can never truly trust your spouse and will always be suspicious they’ll do it to you too—she can’t understand loyalty and is throwing her own insecurities on your relationship. © GellyG42 / Reddit

• Proper response would have been: “Don’t judge my wife or anyone else by your own loose morals. Apologize now.” © 4AuntieRo / Reddit

💡 It’s a striking irony psychologists have often observed: people who have cheated can become suspicious themselves, projecting guilt onto others. That may explain the mistress’s fixation on a paternity test—a symptom of her own unresolved guilt rather than anyone else’s supposed deceit. 💡

• Even if your SIL was not a mistress. She backhandedly called your wife a cheater. Why anyone would expect you to apologize is ridiculous. © jo_dnt_kno / Reddit

💡 It’s true. In family dynamics, an accusation like this is never “neutral.” It questions not just fidelity, but character—a deep violation of respect. So even small provocations can shatter families. 💡

• The “family” can remain broken because everyone is trying to cover up your brother’s shameful actions. He is an adulterer. And marrying the affair partner does not wash away those sins. Not everyone plays in that cesspool, like they do. © grayblue_grrl / Reddit

• Tell your mother to wake up. This woman is poison, and that her first response shouldn’t be smooth over your defense against the woman who successfully helped destroy your brother’s marriage, and is now moving on to destroy your mother’s family by suggesting her granddaughter is, in fact, not her grandchild.
  It’s clear she is deliberately showing the seeds of discontent and misery, with your corrupt brother as her willing sidekick. So silence would only be viewed as agreement and compliance by these people, so why would you endorse that?
  Inform her that you will not allow any of your family members around such an embarrassment again. If she’s that brazen, who knows what she would whisper to your child?
  You also need to stop enabling your mother, my own mam would be horrified if my sibling’s partner said what she did! If your mother doesn’t see reason in this, you have bigger problems than you think. © WelshWickedWitch / Reddit

💡 The mother’s desire to “keep peace” might seem harmless, but therapists warn that forced harmony often hides dysfunction. When a family keeps quiet just to avoid drama, that silence may turn into something more harmful.💡

• On one hand, I think it could’ve been handled better. It takes two people to cause a situation, and you were one of them.
  You can’t control what she says, but you can de-escalate the conflict and be a bit more cloak-and-dagger with your insults rather than shouting and making a scene.
  The right thing to do would’ve been to quietly say, “I’m sure she’s my daughter”.
  The cool thing to have said is: “Well, because we’ve never really had any extra-marital affairs, of course she’s my daughter”.
  If she insists, “How can you be sure”? “Oh, I forgot, you are the expert in extra-marital affairs, no?”
  These cut more deeply, while still allowing people to preserve face, rather than breaking the whole family apart. Don’t be the first one to scream/shout. © Semawhatfor / Reddit

💡 A fair point. Conflict-resolution studies show that humour can defuse tension better than shouting. But when an insult cuts at your family’s integrity, diplomacy rarely feels satisfying. 💡

• Some people have absolutely no idea how genetics works. They make these stupid comments with no thought to the hurt they are causing through sheer ignorance. Good for you for standing up for your wife. © froggingexpert / Reddit

💡 Indeed. Genetic inheritance is complex: skin tone alone can vary widely even among full siblings because it’s influenced by multiple genes. Suggesting someone “should” look a certain way reveals more about prejudice than science.💡

• This is exactly what the phrase “I’m sorry you think you deserve an apology” is for. © ShortWoman / Reddit

• You should buy a paternity test, have it handy, and when they announce they’re going to be dads, give them one as a congratulatory gift. You know what? Better two, so you can also give one for the baby shower. © Pristine-Payment / Reddit

Families fall apart for many reasons—pride, silence, or one cruel comment that hits too close to home. But every once in a while, a story like this reminds us that secrets don’t stay buried forever. 🎬 Ever walked past a truth hiding in plain sight? These people did—and when it finally surfaced, it hit harder than any family feud, turning their lives into something straight out of a plot twist: 10 People Who Realized They’ve Been Constantly Lied To