My wife is exhibiting some strange behavior.?

My wife has a new male friend she met through a mutual friend and recently added as a friend on Facebook. The fact she has male friends doesn't bother me in the least but, what does bother me is the fact he has left inappropriate comments on her facebook page. After a week i stumbled upon the remarks and mentioned it to her , the funny thing is the remarks were pretty blatant and i'm puzzled as to why she didn't catch it first. Another thing is, a new shirt appeared in the laundry and she shot me a weird story on how some drinks were spilled on her friend at the bar and he gave our mutual friend a shirt but, she asked for one too . I find it weird that the average single guy has female shirts just laying around in his trunk . I just wanted to know if i'm over reacting or if i should press the issue.