Obligations of doing anal

I totally understand it when a girl can't take all of a guy's cock in her pussy or deep throat it. Some guys are just too big for a throat or a pussy. Anal is a different story. If a girl takes a guy in her ass, she is obligated to take it all. Her ass is deep enough. Yes, she may have to be stretched more than is comfortable, but I think she must let him stretch her. I have never had a HUGE guy take my ass, but if I am ever lucky enough to have a huge cock I promise I will beg him to go all the way in me. Too many video clips where the girl only takes half of the cock in her ass. That is a total waste of cock. Love clips where the girl takes it all.