Do y'all have any kind of anal play at all?do you lick or suck her ass while giving oral ?if not try it lick and suck and kiss it just like u would her pussy,when she is going to orgasm gently push a finger in and massage her asshole just a little,see if she responds well to it,next time y'all get naked tell her after you have been eating her pussy awhile that u want to love on her asshole,take it from there,with some women its a process,and may not ever do it,but u never know ,I myself can orga