Can you imagine putting a boy in leotard, tights and tutu for a ballet recital?

My gf has had her son in ballet since he was two. He's now five. They have a recital coming up and she and the instructor have decided to put him in the same outfit as the little girls. He has longish hair and is often mistaken for a girl, but I think this is over the top. Am I just phobic or is this a terrible thing to do to the poor kid? (I don't actually think he'll give a hoot right now but when he's old and sees the picture....