WTF!! I don't know what planet most of these people are from suggesting not to confront that friend, Are you kidding me!?!?!?

Lets flip this for a minute, If "your" girlfriend's friend so your a$$ out there with another woman, sh--!! before you got home your girlfriend would be meeting your a$$ at the front door!

Why does this since of loyalty that woman have for one another work for only females and not for men

I would kick my friends a$$ if he knew I was getting played and didn't tell me, It might hurt, but that's a bullet that the home team have to take! ; )