I'm not even sure my wife knows how to masturbate. Even if she does, I'm not sure she knows how to make herself orgasm.
I mean I'm sure she has, but I'm not sure she is very proficient at it. She is just now starting to loosen up in the bedroom and experience orgasms during sex. Until recently (self) masturbation has always been somewhat of an unspoken topic. Over the last year, I've began to take matters "into my own hands" more often during our love making - even as far as to make myself come while she was working a toy in my ass. She was struggling to work the toy and my cock at the same time, so I decided to "lend her a hand", so to speak.
I think this has helped her loosen up a bit too. On occasion, when I'm going down on her, she will dip her fingers into her own juices and then rub it on my cock. The last time she did this, I grabbed her hand and held it there - hoping to encourage her to finger herself. She did for a moment and it was quite a turn on, but I don't think her comfort level is built up enough to let loose and really pleasure herself toward and orgasm in front of me.
But since things are on a steady upswing for us, I'm confident that with a little coaxing - She will be able to let go of her inhibitions and I'll finally get to enjoy watching her get lost in the act of self pleasure.
I would love to experience a session where both of us masturbated while watching each other. Just seems like it would be pretty fucking hot once you hit that threshold where you're no longer doing it for show - but are caught up in the fact that an orgasm is inevitable.