How do I feel up my girlfriend?
do I go over her bra or under?
Over the first few times you do it(same night doesn't count) and then under, unless she somehow communicates by either moving your hands or telling you that you can go under. Usually they're good with it after the third or fourth time, depending on age, I'm not going to look yours up. The younger you are, the longer you wait.
Dont fill up your girlfriend. I'm sure your a nice boy and she's a nice girl and your young. I saw your age just wait. but if you do just go over her bra. at LEAST until you guys are in high school