Seriously need advice 😁

Im 14 and a virgin. I hvs have a boyfriend of 7 months which i know isn't that long but yeah. Im not exactly into doing all this sexual stuff but he is and I just do it because he wants to. We were hanging out last week and we were just watching a movie and cuddling like normal and he just randomly blurted out "can I stick it in your ass?" I said wtf no and he asked again 😁 I said no again and continued watching the film and then he pulled my leggings and underwear down and just tried to do it anyway so I moved away and got out, what should I do? No hate please... Just serious advice