How did you find out your S.O. was cheating on you?

Well I've got a few from my past relationships so here goes.

The worst was finding out on a night out by being told by her uni mates who I bumped into by one of them saying "sorry to hear about you and x, how have you been the past few months" which was confusing so I asked what they meant as we were still together and they replied "oh, she said you broke up a few months ago and has been seeing x since". Was at least comforting having a group of her friends all come over and say sorry and that it was fucked up and they don't want to be friends with her any more.

Another I found out while on our first holiday together. It was a cruise around the med and I asked to use her phone one day she was being weird about it so I found her deleted messaged which she obviously thought were completely wiped and founds messages dating back months from a guy she met abroad while on holiday with her friends. I was worried about her going on a clubbing holiday as she was the only girl who wasn't single and of course the others would get her involved. Found out on the 2nd day so the rest of that holiday was fun!

The last one I found out on new years day which really sucked. My birthday was a few days after and she hadn't even got me anything so had been planning on me finding out. Together for 4 years, have a daughter together and own a house together.

So apparently my relationships have a timer so that after 4 years they just go and cheat on me. Hard to know what the problem is as I always ask and never get an actual reply. I know I shouldn't blame myself but if it's something I'm doing wrong I'd like to know for future relationships.

/r/AskReddit Thread