AITH for defending a cheater and telling my fiancee I am done talking about it?
I recently got engaged to my beautiful fiancee "Heather" and I love her more than anything, but we have one big point of contention in our relationship. Heater despises cheaters. Her dad cheated on her mom and it tore their family apart. Then a long term BF cheated on Heather. To her cheating is a zero sympathy, you are an absolute shit person thing.
The problem is Heather recently found out that my stepmother "Katherine" was the other woman in my parents marriage. She knew my dad before he got with my mom and he always had a crush on her, but some teenage misunderstandings occurred and they both ended up with other people. Years later they had an affair and he left my mother.
I understand that is objectively bad but I am looking at this from my own POV as the child involved. Both of my parents are absolutely useless. Katherine was the only person who cared that my sister and I had baths, a bedtime, healthy meals. When she got with my dad my sister was three and couldn't say a single word. Katherine was the only person who thought that was a problem and she should see a doctor. I'm not exaggerating when I say I wouldn't have anything without her.
My father is only good for making money and my bio mother is good for nothing. Katherine is the only mother I've ever had, and I love her despite the cheating. I've always felt my father only goes through the motions of pretending to love me, because she tells him to and he can't deny her anything.
Now that Heather knows about the affair she is completely different towards my father and Katherine. She is rude to her and speaks horribly about her behind her back. She tells me I should try to reconcile with my mother because she is a wronged woman. Heather has implied that Katherine's infidelity is worse than my mother's flat out neglect.
We were talking about the wedding and she said Katherine shouldn't be in the family pictures because she is "just the other woman"
I finally blew up and told Heather I was done talking about it, and either Katherine can be in the pictures or we can call the wedding off. She began to say but she is a cheater, and I told her I don't care and am 100% done with the conversation. Cheating is bad, but some things are worse. Heather is clearly very hurt and has been distant since.