Wives, if you want to give Hubby a really intimate and special treat, allow him to watch you masturbate, all the way to orgasm. But if you are going to do this, then you can't be self-conscious; if you are shy, as many women understandably are about being watched, close your eyes, pretend you are alone, go to your happy place, and go for it just as you would if you were on your own.
When C does this for me, I don't want her to put on a show, or to try and act like an over the top porn acctress, I want her to allow me in to her private world to share how she truly likes to pleasure herself - I want her to do it for me the way she does it for her, and not the way she might think I want to see.
A nice ancillary bonus, wives, is that he will likely learn quite a bit about how you like to be touched, and how this changes as you approach and reach orgasm.
And husbands, if your wife is willing to do this for you, accept her gift with the gravitas that it deserves - this is an intensely private part of her that she has likely never shared with anyone before, and she is really opening herself up, and making herself totally vulnerable by doing this for you. It is an ultimate expression of Trust and Intimacy for her, and should be treated accordingly. You can't pressure her to do this, it is a gift that must be freely given. And if it is, then watch quietly, and respectfully, learn what you can, and afterwards take her in your arms, snuggle, and thank her appropriately.