Yes, Tara it intrigues me why things like this haven't been developed already but perhaps it is too much work.
I'm not into SM but something like that is enough on the fringe to interest me (I like having my mouth clamped by hand in rl sometimes and it certainly enhances the experience. Oh, and I don't think there are any actions in Achat that enable that either).
I guess the reason why things like this haven't appeared may be that they just haven't developed the model for it. Another example is chokers and anything other than a basic necklace around the neck (the native indian neckpiece being actually an integrated part of the clothing for example). All dresses, tops, skirts, etc. although they may look quite different are essentially all based on the same models. So, apart from hats, makeup, earrings, glasses, there is no basic model for a face piece. Perhaps it is the great diversity of such things that inhibits development. I may be wrong.
The garbling of voice is also of interest. I have difficulty simulating, in text, the sort of noise I might make when my face is buried in someones crotch for example
but text is never a good substitute for sound anyway.