Just like the song by the Goo Goo Dolls, Louis would give up forever to touch Harry. He's the closest to heaven that he'll ever be. He doesn't want anybody to see him because he doesn't think that they'll understand. He bleeds just to know he's alive. Louis just wants Harry to know who he is.
Louis' childhood has been anything other than normal. His parents and family died in a car wreck when he was six, he isolates himself, and he lies, a lot. Not that he means to, it's lies that have been fed to him since his Uncle took him in after the accident. The only person who hasn't cared enough to listen to them...