LDR bf flirting via text and in person with a friend

r/

I (34f) and have been with my boyfriend (34m) for 5 years. 2 and half of those years were long distance.

He went out a lot in these period and I never never minded. Recently, we were having a talk about trust issues and he mentioned a friend used to hit on him while I was living in another country.

I hate the idea of going through someone’s phone. He did that once with me and I was really hurt, but I was feeling insecure and ended up going through his phone.

I found texts between him and this friend being very flirty (with several innuendos from both sides). I know they went out a lot in group contexts. There are quite a few messages from them in the middle of the night including one where they refer to him being handsy in an uber. It doesn’t appear that anything else happened, but I can’t be sure. It’s been 2 years since they have talked (but she also began daring someone in this time).

I really love him and we currently live together, but I dont know what to do. I’ve already been having trust issues with him and seeing these messages- even if they were from a few years ago and nothing happened- still feel like cheating.

TL/DR Any views on this and how to talk to him would be greatly appreciated!