In BDSM, there is no place off limits * obviously this is something you have talked about and agreed on prior to the scene or during the process of submission* Most Doms and Masters like to show thier property off, they like to share with others, be it with others in their poly family or with other friends within the lifestyle, however, that said, most of those I know have always said that the anus is off limits to everyone but them, this is the ‘Forbidden Hole’ the one that is used by the Dom or Master only. Now why this is I really have no idea, it might be because anal sex was something frowned upon up until 10/15 years ago, it was alwas considered ‘perverted’ and not something ‘normal’ people did, how wrong they were !
Anal sex is something enjoyed by most in this life and in the vanilla as well, it is one more step to total submission by a sub or slave when they open all thier body for their Owner to take, to own and make it their own. It could be said that to take it a step further is to then go ass to mouth but that is up to the people involved as it is not something everyone can do.
Anal sex brings another aspect of pleasure into the BDSM life style, just think, how erotic is it to fuck an ass that you have made warm by spanking or paddling ? To have a sub or slave tied with her ass in the air waiting for you to decide what you are going to do, or even if you place a butt plug in while you pound her pussy, an ass hook for added fun, the posibilities are endless and the ass is no longer the forbidden hole to you.