The immediate assumption is just that he doesn't know how to do this to another person. But J... it could just as easily be to himself, too. As unlikely as that seems, if there's anything he knows about his friend, it's that he's the unlikeliest thing Mitch has ever encountered.

His hair free from J's grip, he pulls himself up to kiss him, just a light peck on the corner of his mouth. "Don't worry," he says, feeling stitches scratch his lips, "It's not hard. Just..." He guides the other boy's hand down, to the front of Mitch's opened pants. His breath stutters, and he shifts forward at just the guided, non-participatory touch. Losing himself for a heated moment before he remembers -- teaching. And reciprocation. He slips his own hand down the front of J's pants, wrapping his hand around his cock and giving a demonstrative stroke. "Do what I do."