Hot chick added my boyfriend to facebook?

[tania]

Hot chick adding my BF to facebook?
I noticed the other day in my news feed that a very attractive girl added my boyfriend to facebook (i assume she added him because he was online uploading stuff at the time it popped up). By attractive i mean like WOW attractive, long flowing hair, massive boobs, very fit. When i clicked on her profile she works at the same gym my boyfriend goes to.

For some reason i had this really weird nagging feeling because the only other girls on his fb page are relatives, my friends, or his mates girlfriends.

I can't seem to shake this nagging feeling, because why would a very hot girl add my boyfriend to her facebook? If she works at the gym he goes to every day of the week then they obviously know each other well... should i be worried?