girlfriend digs my roommate...

Ya so the title pretty much says it all, my girlfriend of 1 year has a small crush on my roommate. She isn't in love with him or anything and she would Never ever cheat on me but I just noticed by the way she talks to him that she has a little crush on him. My roommate is one of my best friends and would never even dream of touching my girl but its just the thought of her thinking about him that gets under my skin.
So, my question to you guys is should I confront her about it? Confront is kind of a strong word because I would phrase it very carefully and I wouldn't make it appear as I view him as a threat. And I would also make myself seem as least insecure as possible about it. Or should I just let it slide because it would never amount to anything?

I would really appreciate your guys' advice on this.

deleted