The bottom line is, it's a cheating issue.
What's funny, is that there's so many different kinds of dishonestly/cheating. I mean, emotionally cheating seems almost as bad as physical. So, while there might not be any proof of physically cheating, the fact that I read this email from another girl (and I checked the email on purpose, because I did have some suspicions) who is married, by the way, and they are talking about things he's never even told me about... I don't know, it's enough to make me suspicious.
And now what's worse, is I don't want to be dishonest...
