Her first solo orgasm

My wife likes to have fun with toys and porn, but always together, she never discovered how to orgasm during masturbation. I would like her to teach herself, so she could have sexual fun when we can't be together or... to put on a hot masturbation show for me. My fantasy is that I teach her to do it in the following scene:

I tie her to the chair. I put a scarf around her eyes. I turn on the big TV on the wall and start playing the porn she likes. I leave the room for a few minutes and when I come back I see a little moist stain on her underwear. I take off her underwear and the  blindfold. I smile and she smiles back. Now she not only hears the movie but can see everything in detail. I leave the room again. When I come back I see her gazing intensely at the screen, immersed in the action going on. She obviously likes the experience, I can see that by her hips moving slightly, forward and backwards, and her dripping pussy. She asks me to satisfy her with her favorite vibrator. I tease her with the toy, demanding to tell me how badly she wants it inside before doing so. When she starts to shiver, close to orgasm I untie one of her hands and say 'you have to take it yourself if you want to come', with a cruel smile. She doesn't care now about anything, she is released from her inhibitions, grabs the vibrator and fucks herself deep looking right into my eyes. She gets her first self-made orgasm moaning loudly and shivering vigorously. Since that important moment she likes to masturbate in front of me from time to time, which makes us both happy and horny...