AITAH for breaking up with my GF because she’s still friends with the guy she cheated with in her previous relationship?

A 26-year-old guy and his 25-year-old girlfriend had been together for about a year when things unraveled during a casual hangout with her friends. They were playing a quiz game when the topic of cheating came up. He casually said he hates cheaters. Suddenly, one friend shot his girlfriend a knowing look, and she got visibly uncomfortable. That awkward moment stuck with him.

The next day he asked what was up. She admitted she cheated on her previous boyfriend—once, while drunk, with a guy we’ll call B. B was her former friends-with-benefits, and they still hang out regularly as friends. He’d known about their history and tolerated it, but this new info hit hard. After two days of thinking, he broke up. He didn’t want to demand she cut B off, and he knew he couldn’t handle the friendship—so he walked away. Now he’s wondering if he’s the asshole.

‘AITAH for breaking up with my GF because she’s still friends with the guy she cheated with in her previous relationship?’

It all kicks off during a chill game night with her friends:

She comes clean:

This situation boils down to trust and boundaries: past cheating can sometimes be forgiven, but keeping a close friendship with the affair partner is a massive red flag for most people. She hid the cheating (lying by omission), and her ongoing contact with B—the guy involved—makes her current partner feel understandably insecure.

Many argue that if she truly regretted it and valued the relationship, she’d have cut ties or at least minimized contact with B to give her boyfriend peace. Prioritizing that “friendship” over his comfort shows a lack of full commitment. His decision to break up instead of demanding she drop B was mature—he chose self-protection over control or constant doubt.

Relationship expert Dr. Esther Perel, author of “The State of Affairs,” explains: “Infidelity isn’t just a one-time act; it leaves lasting scars on trust. When the third party remains a regular presence, the betrayed partner struggles to feel safe. Forgiveness is possible, but it requires total transparency and real changes—not keeping everything the same.”

A better path for her would’ve been full disclosure early on, and willingness to adjust the friendship if it caused pain. For him, walking away rather than trying to force change is healthy. Real-world advice: trust is the foundation of love—if a past behavior keeps causing ongoing anxiety, listen to your gut instead of forcing acceptance.

Here’s the comments of Reddit users:

The internet overwhelmingly backed the breakup, calling it a “huge red flag” and praising him for walking away cleanly—only one comment wondered if the cheating might be more recent:

Most readers saw this as a non-negotiable dealbreaker, applauding his self-respect:

One lone comment suggested the uncomfortable look might hint at something more current:

This story shows how past infidelity can haunt a new relationship—especially when the affair partner is still in the picture. Most agree the friendship was too big a risk, and breaking up was the healthiest choice.

What do you think? Would you stay if your partner kept close ties with someone they cheated with? Or is that an instant dealbreaker for you? Share your take below—we’d love to hear!