Silent treatment is never good. He should work on communicating how he feels.
Besides that, It’s appropriate to look at situations like this from both angles, stripped of sexes, emotions- but needs. In this moment, One has a need for sex while the other doesn’t. For the one who doesn’t, the outcome won’t make much difference, because they still end up with the result they’re after- no sex. However, for the other, the result they are trying to achieve is blocked and cannot be fulfilled causing frustration (which is an emotion closest to anger. Some men resort to it more quickly because it’s most available when you’re emotionally unintelligent about your feelings and reasons.) In this case, nobody is wrong, it’s just a contradiction of needs that causes incompatibility between two people who are “committing” to one another. This person cannot meat theri sexual needs anywhere else, most likely this is a monogamous relationship, which casues the frustration, because after being denied, the person is left with their sexual tension built up so high and left unsatisfied along with the knowledge that they cannot go elsewhere to satisfy it. Sure they can jerk off, but the perks of a relationship is to experience the real thing and not have to rely on your own hand to meet that need. In the animal kingdom, you’ll find many animals rarely if ever masturbate, but then again, polygamy keeps them all from getting to that frustrated place. Best advice, work out a compromise for meeting each other’s needs when they conflict.