He first appeared at the end of Thanks for not morphing as a handyman. In Wicca Envy he 'heals' the Book of Shadows to give the sisters their powers back. In Secrets and Guys Phoebe discovers Leo's true identity kwa seeing him floating in the air, replacing a lamp. In upendo Hurts Piper and Prue find out too, when Leo literally drops in, injured kwa a Dark Lighter arrow. In the sekunde season Leo and Piper try to make their relationship work, but Leo always has to leave unexpectedly, so Piper breaks up and starts dating Dan. In Awakened Leo heals Piper when she's in the twilight zone, and the elders clip his wings. Now that he's a mortal he wants to fight for Piper and in Give me a sign Piper realizes she wants Leo. In How to make a quilt out of Americans she breaks up with Dan and Leo and she become a couple :)