Help. Criminal related. ?

Okay so about 6 months ago I went to go hangout with this guys with my friend that's a girl. We went to the movies etc and we ended up getting drunk. I was 15 at the time and I had sex for the first time with one of the guys. We were both under the influence. He was 17 but his birthday was the next day. I came home and my parents saw me and are now pressing charges. I got a subpoena on Friday to testify. What is gonna happen to him?