Leo: I don’t know, but I’m feeling really nauseous.
Piper: Oh, god. And I’m not. Wait…how…why…why does he have my pregnancy symptoms?
Cole: W-wait. W-what? You’re pregnant?
Piper: Well, I was, but now I think Leo is.
Leo: No! No, no, no, no, no.
Episode: Siren Song
Piper and Leo argue and baby Wyatt swaps their powers, also causing Leo to feel the symptoms of Piper’s pregnancy.