I don't think I am ever gonna masturbate again..?

Ok I only feel free to tell what ever I want on here so here is the whole story.. So My friend had a sleepover and it was me and like 9 or 10 other girls. So I really like my friends brother who is a year older than me and he likes me too. But he was at the house too but he was upstairs and we were in the basement, so, we were playing a game like truth or dare but it was no truth just dares. And one girl dared me to masterbate. And if I didn't take this challenge she would go around school saying i lost my virginity, so I had to do this. So she dared me to hump a pillow and put a picture of my grinds brother who I like in front of me so It would be like having sex with him. So I started humping to the picture and the girls were laughing, I was too cuz iw as gonna dare the girl to do this next. But while I was masterbating to the pic of her brother her brother came down stairs and saw the whole thing. He looked shocked and kinda disgusted. So what do I do?