Most Helpful Guy
Sometimes I wonder if guys do this because they are bored with their current relationship or feel somewhat neglected. I know what he did was a douche bag move, but it may be a cry for attention because he feels you aren't giving him enough. We all want and like to feel desired, so you might have to up your game a notch with him so he doesn't wander.
Most Helpful Girl
I don't know I mean I would be mad to if my boyfriend told a group of girls his dick size. You have the right to be upset. It made you upset because it's almost like flirting he was telling those girls so he can a reaction from them.