Photo of me leaked out

So, was on a sleepover with 2 male and 2 female friends of mine, who i considered my friends. So, we go to bed last night to sleep. and I wake up and figure out that at the middle of the night the 2 girls have pulled my pants down, and taken a picture of my erect dick. Once Im completely away, I ask them to delete it, but it is already sent somewhere. When I ask where they sent it, they tell me to a girl groupchat. And so, I get angry, start threatening that I will press charges, until one of them says she will do me a favor, blinking her eye, but in a future time. I do not really mind the pic leaking out in school, because it will have positive effects along with the negatives. But I still want to cut contact with these two girls because they could have just asked me, instead of violating my privacy and trust. What should I do?