Hi B.,
When he's playing outside, do you notice anything he seems to particularly enjoy? Like running, kicking, anything like that? I know what I'm trying to say, but I can't think how to put it....
My son, he liked batting, and hackey sack, kicking the ball, running, stuff like that. He did soccer for 3 years, and then grew out of it, did t-ball for 2 seasons, didn't like it, and basically, we just let it boil down to letting him ride his bike and play outside with the other kids. We would have encouraged sports if he'd shown interest, but he never did. Oh, he didn't like tae kwondo(sp?) either. Now, he's a gamer, and not into sports at all, and one would think he'd be overweight, but he's not. He actually swims at school everyday, and he loves that, so I guess you could say he's a swimmer, but not competitively.
Maybe with your son, either take him to the park/playground on good days and let him interact with the other kids, and do what he feels comfortable doing there. He'll more than likely find some kids there doing something he likes. Or, check out the "Y" and their kids' programs. They also have swim classes, and it's something you could consider getting him into.
Also, think about this: reality is some kids may be teased, probably all are at one point or another. There will be times when you can't control every situation, so even if you know it's happening, you may have to let him be exposed to it, just so he'll learn how to handle it. If you teach him value about himself, and self-esteem, then while their words might upset him, he can look at it as something wrong with them, not something wrong with him. The only time you should intervene, is if you know it's hurting him emotionally(irreparably) or physically. You should probably ask him if what they say bothers him enough to make him want to quit. Then maybe you should let him know that if what he's doing is something he really wants to do, then he needs to try, so he can make himself proud that he did his best. Then, if he's tried his best, and still does poorly, thenit's not for him. But also, you shouldn't make him stay in something that he really doesn't like or really can't do.
Find what he likes and what he can do. Every kid has something they like.
Good luck to your family, esp. your son. He's lucky to have you. :o)
K. W