Greg is best friends to The Twins, an only child and mildly jealous of the brothers. The teenagers had all discovered masturbation, but The Twins let on that they sometimes wank each other. Greg wishes he had a brother, or a friend, who he could wank with. After school, The Twins decide to give Greg what he wished for.
I’m surprised that the twins wear clothes to school, they seem the naturalist types. Unless the parents don’t allow it. But then again if they object, why are they in cockainge?