Heads Up, Blobberts! - S4.E4

Kurt finds out he can remove his head. His body, without his head, is not a wimp and starts playing a new sport that makes him really cool. However, after the body starts going steady with Megan, it ditches Kurt's head and he is given the advice 'Your head is where the heart is.' Later on, the body gets really mean and they think up all sorts of ways to put Kurt's head back. However, when they find out the head really is where the heart is, it has to be put back so the body is nice again. Because, without the head, the body is just a nasty loser.