Name change for this as some of my other posts are possible outing and as this is about my brother I don't want it to be linked back.
My brother has been with his DP for 7ish years. There has been cheating rumours in the past, she's been caught texting other guys but never admitted to anything concrete. My DB forgave and they moved on. He obviously hasn't moved on as much as I thought he had because he's checked her messages and found a conversation that doesn't sound great. She is on a girls holiday at the moment. I don't want to write the specifics of the messages for fear of it being outing (I'm 99% sure she's not on here, but I don't want to risk it) however the message he is most worried about is her asking the guy she was messaging where his hote was in the early hours of the morning. The last message was her staying she had had to much to drink last night.
My DB is asking my advice, and I really don't know what to tell him. I like her and I'd like them to stay together so I guess that clouds my judgement.
I have told him I worry the trust is gone if he feels he needs to check her messages and that's not a good basis for a relationship. I've told him he needs to talk to her about it, but she has already been through her messages and deleted the chat (he has screen shots) so is obviously covering her tracks. Any advice from the wise world of mumsnet?