How do guys talk about their girlfriends when we're not there?

dml17
I have an awesome boyfriend of about 3 months; he is a senior and I am a junior. We get along great and his friends seem to like me. Today he was giving me a ride home from school and two of his other friends were in the car. They were talking and joking with me on the way, but as soon as I slammed the door I'm pretty sure I heard one of them go "whoo whooo!" (!) and it made me wonder:

I think my boyfriend might brag about sexual stuff we've done together. How much do guys tell their friends about their girlfriends and what do you say about them?
How do guys talk about their girlfriends when we're not there?
2 Opinion