While he isn't aggressive when his feelings are hurt, he turns pesky - l am guessing it is things like flipping a shirt collar as he walks by, putting a foot on them under a table, bumping into them "on accident".
My son is like this too. For him it's more mischief for the sake of fun, rather than being retaliatory, but the end result is the same in that the other boys get irritated. They'll even get to the point where they'll band together to play pranks on him, but fortunately that doesn't happen often. These are boys that my son wants to play with and is not sure how. Fortunately he has another group of friends who know him and "get" him, that like him and are kind to him.
