Help.!

(I didn’t know where else to post this)

So there’s this guy that I really like, we started talking and he was sweet at first then he started asking for pictures and when I didn’t want to send him pictures he got mad and stopped talking to me. We started talking again and he was being really weird and sexual he would always ask me if I would let him finger me and I always thought he was joking. One day he invited me to the park and he just kept touching me and trying to do stuff, I’m not ready but I feel like I’m never gonna get a chance if I don’t let him and I really like him. What should I do.? Any advice.? We are both 14.