For some reason, this form of masturbation has been stuck in my head. Maybe it's just that I miss being able to curl over myself the way I used to.
A buddy of mine from the military days once said to me, "Shit, if I could do that, I'd never leave the house!"
He was also quite open about jacking off. His wife enjoyed watching him from across the room as he stretched out on the couch and stroked and teased, massaged his balls. Seeing his sexual tension flow and ebb, to see how he altered his grip and speed, the areas of his body that he stimulated, was a great learning experience for her.
And, he admitted, she got much better at hand jobs - whether it was a quick one if he showed up at home for lunch, or a long, sensuous session right after he walked in the door in the evening to help him relax.
He claimed she got better at sucking his cock, too, as a result.
But, at the same time, she never felt cheated if he said he preferred to shuck his clothes, kick back, and jack off.
All you straight dudes...you really need to come clean about this. The second most prominent argument in relationships is over sex. The more openly you can discuss these things, the better off you'll be. And the more satisfied your balls will feel if you can get them off when and how you want.