I honestly wouldn't worry too much. I personally have more male friends than I do female. My ex and I used to argue a lot about innocent things like that. I actually came to realize that a lot of the guys I thought were being nice to me because they valued me as a person really just wanted to get into my pants, but my intentions were always innocent. I think your girlfriend may be a little bit naive, or maybe she knows he's interested in her but she still likes him as a person and wants to continue the friendship. Us women tend to do that sometimes because we feel like we can handle it. Regardless, I honestly don't think you have anything to worry about.

And FYI: My ex used to read my texts, check my phone records, and constantly question me about them and yes, it really hurt me. I would NEVER do something like that. I'd show him willingly if he asked, but the sneaking behind my back was such an insult and invasion of privacy. Watch yourself with that, especially if it was one of the issues she had with her ex. Don't let a stupid thing like that be the catalyst to ending your relationship. Believe me, it can.