A sacrilege to keep it a

Stiles has a secret he's been keeping from everyone his entire life. But Derek is starting to notice the fact that he'll never go near a body of water when other people are around and he keeps saying that he's really bad at swimming. Derek knows that's a lie because he was able to hold him up in a pool for three hours straight.Stiles knows his secret is a ticking time bomb and at some point, everyone will know it. But he quite likes being the human of the pack. Even though Derek and he know that he isn't.Derek just wants to figure out exactly what he is.