Guys....what would you have felt/done?

I met my GF back last October.... while I met her she was talking to one of my friends and after about a month that ended. Also, while we were talking she had a few of her guys friends spend the night. We went October,November,December, and most of January without fighting or brining it up. However, in January.... we brought up our past relationships as serious couples usually do. She told me that she slefpt with that friend of mine 5 times in 6 days after they had only been hanging out for around 13 days... she also said that when those 2 boys came up she got really drunk and slipped down to her bra and thong for them and danced with them. I of course got mad and we started to fight a little after that... At the pt when we brought it up I really loved her and I felt really hurt and sad and at times said some hurtful things about it. In early May I finally got over it but she said that it took to long and I was immature for it. Guys...how would you have felt or handled it?