Relationship opinions please?

Well hello people i am 17 years old and ive been with my girlfriend 8 months exactly. My issue is when it comes to sexual stuff. This girl has done sex and other stuff with all these other guys i think 3 or 4. She's my first one. I can't get over the fact that she's done that with other guys and it's my first time, i know, i'm dumb. But i can't get over that because she actually specifically told me what she did with each one..like as in oh, with the first ex i did *ral and second ex i gave him *ead and a *andjob and with the 3rd ex i gave him a *andjob and got one too. Um yea i can't get over her saying this it's nasty in my opinion, yet she argues that she didnt know being this specific was wrong and that her specifically describing what she did with each guy is right. Do you people think this is right? I find it disgusting since she's my first.