Anal sex ??!! Helppp

My boyfriend loves to have anal sex , but i dont realy like it cause it hurts alot but iv tried it with him 2 times it hurts alot and i was screaming and after we finshed my butthole and my vagina and his dick was full of waste and the smell of the waste all over the room i was very embarrassed this happend in the 2 times what should i do ?????