I finally got Mr. J to go roller skating with me. He did really well, for never having been on roller skates in his whole life (though, seriously, how do you live through the seventies and eighties and never roller skate?). He stumbled around for a bit but he really got the hang of it after the first hour. And he totally didn't bite it.
He made vague promises about going again with me. Soon everyone I know will be roller skating and I can finally have that dance troop I've always longed for.