Forgiveness

So I’ve been with my boyfriend for a year and a half and although it doesn’t seem like long out of any of my relationships I’ve always been the closest with him and I really care about him. A few months ago I caught him talking to these two girls, one out of state and he was flirting with her and telling her she was cute and sexy and stuff and the other one was his ex and I don’t know how much they were talking but all I read is they were planning to meet at his house and drink after work but he swears it never happened. Other then these two things we’ve had a great relationship and he seems to really care about me and love me and I really want to get past this and try to trust him fully again, even if it means that it might happen again(in which case i made it very clear our relationship would be over), I’m wondering if there’s anyone else out there who has been in a similar situation but eventually learned to forgive him/her and trust them again. I really want to work past it but of course it’s a lot easier said then done. any advice?