Myy wife's bull knew she did not want anal sex and for a few sessions he was ok
Then slowly he started introducing her to anal stimulation -rimming, fingering, just inserting the tip of his hard dick just slightly in her ass and finally one day he just started shoving it in her ass
He held her down with one hand and used his well greased and lubed dick and took her anal cherry
He always fucks her bareback and he dumped his load in her ass
She was whimpering and complained that it hurt but knew that he wanted to claim her ass for him
Now he fucks her in any hole he wishes
He is 10 inches when hard and thick like a coke can
I think the key is to start slow and introduce the slut to Anal pleasure slowly eventually they get hooked and if not at least tolerate to please the bull