Seriously though, this is what I would do: buy a hidden camera, leave it in his bedroom or wherever there is a computer, and catch him on tape doing something like masturbating or having sex. Then blackmail him and make him your bitch.
But this depends on how dangerous he is. OP, compared to him, how physically fit are you? (I would imagine he's very fit since you said he's a soccer trainer.)
why would he be intimidated of a recording of him yanking it or having sex? This ain't high school. if anything he can threaten the op with invasion of privacy if s/he does that.
