It's more weird than gross at first; he grows until he is the world's hugest pigeon, and then his feathers and beak all slurp away and he is briefly a giant horrifying nightmare pigeon, and then his skeleton rearranges itself with a disquieting grinding noise and his hair sprouts all at once and there is a general wriggling of flesh into place, and a teenage boy is sitting on her bed in his underwear.

"Hi," he says, bouncing a little.