The last episode of season 1
Leo and Piper do not die in the Hereos of Olympus.
I do not know the name of the episode but I am pretty sure there is at least one episode were Leo tickles Piper.
Leo and Piper get married in the third season and I think that its on the fourth disc. The episode's name is "Just Harried."
He only tells Phoebe and Paige. Phoebe and Paige tell it to Piper. Leo finds out from Phoebe.
Scry Hard
no
Piper finds out in 6x16 and Leo in 6x18
annabeth, leo, piper, and percy
Well, honey, Piper and Leo make out at P3 in the episode titled "Love Hurts." So, grab some popcorn, sit back, and enjoy the show!
Piper McLean, age 15, is a daughter of Aphrodite and a Cherokee movie star. Leo Valdez, age 15, is a son of Hephaestus. Jason Grace, possibly the same age, is a son of Zeus (Roman equivalent: Jupiter). He is the younger brother of Thalia Grace.
Wyatt Halliwell, Piper & Leo's son
Piper and Leo have two sons - older Wyatt Matthew Halliwell and younger Christopher Perry Halliwell.