Woman Cuts Off Sister For Dating Her Cheating Ex-Boyfriend Who Gave Her An STD

Content Warning: Cheating, Sexually Transmitted Diseases

We've all heard of the Friend Code or the Sibling Code, in which we won't date someone our brother, sister, or friend previously dated, at least without talking to them first.

While most people are fairly open to honoring that, there are some people out there who feel so entitled to date whoever they want, they ruin important relationships in the process, cringed the users of the "Am I the A**hole?" (AITAH) subReddit.

Redditor Extension-Simple7312 was in a relationship with the man who she thought was the love of her life, at least until she found out he was cheating on her, and again when she found out that she'd contracted an STD from him that he'd picked up during one of his affairs.

But when her sister decided to date the same man, despite her past history with him and mental health, the Original Poster (OP) decided to cut her sister out of her life, permanently.

She asked the sub:

"AITAH for telling my sister she lost me the second she even considered dating my ex who gave me an STD and didn't tell me?"

The OP thought she was in a loving relationship... until she wasn't.

"I (28 Female) was with a guy called Jason (29 Male) when we were 20/21 years old."

"We broke up when I was 22 after I'd found out he had not only cheated on me, but also knew he had contracted an STD from sleeping around and didn't tell me. He had known about it, and he was told he needed to speak to any sexual partners because of the risks associated with this STD to fertility, and he said nothing."

"I remember when I told my family what had happened, they were all there to support me and my sister (27 Female) was one of them."

Fortunately, the OP was able to build a new life for herself. 

"I did move on, and I met my husband a year after breaking up with Jason. And thankfully, I was able to get pregnant and we have a baby together."

"But I never forgot about the fact that Jason did what he did."

"Cheating was bad enough, but you can move on. The STD was where it became not only unforgivable, but I would have taken issue with anyone in my family even becoming friends with him after that point."

But then the OP had to say goodbye to a loved one.

"But then, three months ago, my sister asked me if I would be okay with her dating Jason."

"She told me she didn't want to lose me, but they had met again after several years, and she liked him and he'd changed."

"I walked away from my sister without saying a word, and she started dating Jason officially. Though when she came to me like she did and asked me like she did, I would guess they had been unofficial before that point and not just friendly."

"I have shut my sister out of my life, and she has not been allowed to come and meet my child."

"The rest of the family stands by me and what I decided, but they have not shut her out of their lives, which is totally fine and not an issue for me."

The OP's sister kept trying to regain access to her life.

"But my sister doesn't like that, and she has tried to get in touch with me several times and has cried and asked me to hear her out and to talk to her. The fact that I have run into her once since, and I ignored her. She was talking to me, but I acted like she was a ghost I couldn't see or hear."

"So she ambushed me at my house the other day and told me she doesn't want to lose me, and she'll break up with Jason if I stop ignoring her and we can go back to being sisters."

"I told her she lost me the second she even considered dating him. I told her I might not have known about it in that moment, but once I heard she wanted to date him, knowing what he did to me, it was over."

"She's crying about it now, and our family is refusing to hear her cries about it."

The OP assumed that more pressure was coming in the not-too-distant future.

"My baby sister (24) told me she's trying to get the rest of the family to confront me about it, but nobody will. She does think our sister is genuinely hurt about this, but she feels like it's her own fault."

"And I agree. But I know what I said to her might still be overly harsh because even thinking about it without acting on it would have led to this, which might be wrong of me."

"So I'm here to ask, AITAH?"

Fellow Redditors weighed in:

• NTA: Not the A**hole
• YTA: You're the A**hole
• ESH: Everybody Sucks Here
• NAH: No A**holes Here

Some immediately argued against the sister's statement that the cheating ex had "changed."

"People who are bad people, cheaters, abusers, etc, have a charming and likable side. That is how they get their victims or partners."

"I am always amused when someone says, 'No, he's changed.' Has he? Or is he just showing you the side of him he wants you to see?"

"If he has changed, can the sister articulate how he has changed and what drove him to change? How has he made amends, or at least acknowledged the person he was?"

"In 99.999999% of the 'He's changed' cases, he has not changed at all; he is just in the love bombing stage. The person who believes he has changed almost always finds out the hard way that he is still a cheater, still selfish, still dishonest." - AdAccomplished6870

"It's possible but exceedingly rare for these kinds of people to genuinely change. Personally, I think if he had changed, he wouldn't have pursued the sister of someone he'd hurt the way he did."

"He'd be able to recognize how wrong his previous actions were. He'd know he didn't deserve forgiveness from his previous victims. He wouldn't want to risk hurting them ever again."

"In my opinion, this guy doesn't care about his previous victims. He doesn't care how much pain he's caused to the family again. He has not changed." - MykelMoney

"Out of all the available women in the world, he just happens to think the sister is the special one for him now? Bulls**t."

"People CAN change, particularly as they naturally mature from teens to adults. Granted, some don't, and a LOT of men take quite a while. But I would still consider my 20/21 year old self quite different from my 27/28 year old self."

"However, why of all the people in the world, the sister? They obviously always wanted to bang, I wonder if they didn't back then..." - ked145

"He has changed so much that he is happily perused and is staying in a relationship with someone, knowing that it is destroying her relationship with her family." - InternetTurbulent769

"Sister, whining voice: 'But he's chaaaaanged!'"

"Morgan Freeman voiceover: 'He had, in fact, not changed at all.'" - qwinflavour

Others simply reassured the OP that she was right to be upset about what her sister had done.

"The boyfriend placed OP in a situation of possible irreparable harm. In that situation, you ride and die with OP. It is forever and always 'on site' if you see the boyfriend. You don't actually have to fight, but you certainly don't give them a chance to explain how they changed."

"The boyfriend could become a priest, and those of us who know how to ride and die know he has not changed and does not deserve forgiveness."

"The sister will be his next victim, no doubt, but she has had intimate knowledge that I'm sure we don't even have, and what we have is enough to know the decisions she has made were grave mistakes." - Appropriate_Tie_8180

"He was with OP for almost two years, and it was OP finding out on her own about both STD and cheating basically at the same time. I give about the same amount of time or more because sister is delusionally entitled and in denial of basic facts and reality compared to OP, who legit had no clue what level of a piece of s**t he was while being 20-22 at the time."

"NTA. Both OP and the family are correct for handling this situation how they see fit, OP by cutting off and family by basically do, 'Well duh, what did you think was going to happen if you did that...'" - maywellflower

"NTA. I'm honestly confused about why she thought you would be okay with this? Also, who even wants to date their sibling's ex?! I'd never think to do that to my sister, nor would I want to." - CAgirl17

"NTA. Your sister seems to think that Jason is the issue, and if she gets rid of him, it'll undo the damage. The thing is that he isn't the problem. She is."

"She deliberately chose to date your ex, which in and of itself is weird and wrong, but she didn't just choose any ex. She decided to pick the guy who hurt you the most, who cheated, and who willingly gave you an STD, knowing it could cost you your chance at having children."

"All that is bad enough, but the fact that she crept about meeting him and began dating him without mentioning anything makes it worse."

"She didn't speak to you about it before anything happened to see how you'd feel, she basically went, 'Hey OP, you know that guy who broke your heart and jeopardised your health all so that he could bang other women? Well, I'm banging him now! We're totally a couple! Isn't it great? He's totally changed, so you're going to be cool with this, right?'"

"The damage was done the moment she decided to get involved with him in any way. She made it clear that he and his wandering penis were more important than you, your feelings, and her relationship with you. I have to ask, what do you think she expected with this? Is she normally this thick-headed and oblivious?" - Buttered_Crumpet09

"Definitely NTA."

"She knew what she was getting into. She saw how he treated you and supported you during that time. Just because he announces that he changed doesn't mean you want to be around him."

"Stick to your boundaries. I'm glad there were no underlying and long-lasting health issues from your time with him." - Deep_Rig_1820

As much as the sister wanted to have a relationship with the OP and her current "boyfriend," it was clear that trying to have her cake and eat it, too, was exactly what caused the cake to irreparably fall to the floor... and the five-second rule did not apply here.