I have to keep my bfs away from my girl friend...

My bestie is everything I am not.

I am taller than average, I have a thin, athletic build and I have glasses and struggle to maintain a halfway feminine appearance. Most of my friends are guys and we typically work on trucks or read comic books.

My bestie is almost like my altar ego. She's short, cute, feminine and has nice skin and hair. She enjoys shopping, reading and pretty much everything that bores me but we have a good time. Our friends compare us to lesbians and she is the woman in the relationship... Where they say I'm the man!

I have dated four men over the past four years. All four were totally different men, all four were great relationships, all four tried to make a go at her. A couple of weeks ago, I introduced my current bf who I've been with for about a year now... And this bloke seemed to take an incredible liking to her. He added her to his Facebook and speaks to her occasionally... He's given me no solid reasons to be suspicious but it may be due to my telling him in conversation how she came to me with the last three guys.

I'm not going to bother him about it without reason and I've expressed my concerns, all of which were met with reassurance. All the while, it looks like history is repeating itself.

I don't know what the hell to do. Is this normal!?