Woman Betrays Sister For Her Cheating Ex With An STD, Shocked When Sis Cuts Ties With Her For Good

You know the saying “Once bitten, twice shy”? Yeah, well, betrayal hits different when it comes from someone who’s supposed to have your back. Whether it’s friends, lovers, or your own flesh and blood, there’s nothing quite like the sting of realizing someone sold you out faster than a TV on Black Friday.

Family betrayal isn’t just a knife in the back – it’s the whole darn cutlery drawer, and our Redditor knows this all too well. She cut her sister out of her life after she started dating her cheating ex, who gave her an STD.

More info: Reddit

RELATED:Blood might be thicker than water, but not when it’s contaminated by your sister’s terrible taste in men

One woman cut ties with her sister after discovering she’s dating her ex-boyfriend, the same guy who cheated on her and gave her an STD

The woman’s ex cheated on her with multiple people, contracted a fertility-jeopardizing STD and never told his partners about it

A few years after their breakup, the woman’s sister told her she ran into her ex, and asked her if she would be ok with her dating him

The woman cut her sister out of her life after finding out she is dating her cheating ex, not allowing her to meet her child

The OP (original poster) dated a guy, Jason, back in her early 20s. Things were already bad, as he cheated, but the worst part came when she found out he had contracted an STD from all his side quests and failed to mention it. This dude skipped the entire honesty chapter of the relationship handbook.

Even worse? The STD came with fertility risks and doctors explicitly told him to inform his partners. But Jason decided to go the “silent but shady” route. Thankfully, the OP was able to treat it, move on, and now has a healthy baby with her husband. Case closed. Wait, not so fast.

After a few years, the OP’s sister suddenly hits her with a “Would you mind if I dated your cheating, health-jeopardizing ex?” claiming Jason had “changed”. Sorry, but unless his new personality came with a notarized apology and a blood test, that’s not going to cut it.

The OP walked away. No words. No hugs. Just emotional damage. But that didn’t stop her sister from dating him anyway. So, the OP shut her out. No calls. No baby visits. Just silence. But guess who couldn’t handle the silence? Sis suddenly realized actions have consequences (who knew?) and started trying to crawl back.

She ambushed the OP at her house, offered to break up with Jason, and pleaded to go back to being sisters. But the OP’s response? Brutal honesty. “You lost me the second you even considered dating him.” Now sis dearest is crying but the rest of the family is siding with the OP.

So, is she a jerk for cutting her sister out of her life? Well, let’s recap: Jason knowingly endangered her health, her sis knew the whole story and still thought dating him was a good idea. So no, the OP is not the a-hole. She’s just someone who survived betrayal and rebuilt her life.

Because when betrayal comes from within the family, the sting can be really painful. Family betrayal is personal, deep, sticky, and weirdly isolating. When a family member crosses a line, it hits at the core of your identity. But healing doesn’t mean you have to keep them in your life. Forgiveness is optional, but it’s for you, not for them. After all, you don’t want to carry that betrayal trauma around forever.

Betrayal trauma isn’t just a dramatic plot twist—it can actually mess with your brain. When someone you trust deeply breaks that trust, your body reacts like you’ve been hit by a truck. The pros say that betrayal trauma can come with anxiety, nightmares, hypervigilance, memory issues and even affect your relationships, self-esteem, and ability to trust.

Healing takes time, but it starts with acknowledgment, support (therapy helps big time), and giving yourself the grace to be hurt without needing to rush the “forgive and forget” part. Because once trust breaks, it doesn’t magically glue itself back together with good intentions. Rebuilding trust is all about consistency, transparency, taking responsibility, and time, lots of time.

What do you think of this story? Is the poster a jerk for cutting her sister out of her life? Drop your thoughts and comments below!

Netizens side with the woman, saying she is not a jerk for cutting contact with her sister