sex with the bf

so me and my bf are basically having sex everytime we see each other which isn't that often its like once or twice a week but each time he gets more adventurous i told him no butt stuff and when we doing it doggy style he keeps trying to put it in my butt as if im not paying attention i turn around everytime and tell him no and he is like you sure and my like yeah im sure i dont want your dick in my ass and its not like he does it once in a while its like several times in the same day ugh 😣😖😡😠😤😬😬😬😕😕😐😱😱😨😨😡😡😤😤😤