My bf has a dog and its penis is very huge. I am thinking about it every day. How to hint to my boyfriend that I want him to force me to be a bitch for his dog?

My bf is a dom, we have lots of sex, he forces me to rim him, suck his balls, drink his pee, but I want to go further. I am afraid he will abandon me for degeneracy if I ask though. I’ve seen him scrolling some bestiality art so maybe I have hope??