My fiancé and I are very happy together, engaged last year, live together, been on plenty of holidays together, and I help look after his daughter on weekends he has her.
however, about a year and a half ago, the mother of his child (not exactly an ex as he said she was just a sex thing to him and she developed feelings for him but he never wanted to be with her) messaged me and sent me screen shots of what’s app sexual messages and images (penis pics) my partner sent to her. It broke me at the time but partner swiftly apologised and said it was a one off moment of madness when he was working away. We had a long walk on the beach and he swore he would never do it again. I know for sure he hasn’t as after this moment he stopped communicating directly with mother of his child, she has mental health issues as it is and even tried to commit suicide after he refused to communicate with her again.
fast forward to now and we are happy and engaged, our relationship looks perfect from the outset, however I cannot get this incident from my head - I still feel insecure and jealous that he did that, and it plagues my mind often. She is very attractive and intelligent and I can’t stop feeling I’m inferior to her. He says the mother of his child is a drama queen and just wants to cause him and us misery hence why he never speaks to her anymore. I’m glad he doesn’t as I’d be worried of a repeat if she messaged him again.
my question is - when will this one incident stop plaguing my mind in my otherwise very happy relationship? I’ve not told any friends or family about it, his family don’t know of it either, I’d be too scared to disclose it to anyone I know really in case they judge partner badly for it.