PIIHP Share definition Flag Shorthand for "Put it in her pooper." Refers to the will to stick your dick up a girl's ass and bang the living hell out of her. "Dude Matt...just PIIHP and run away fast. She'll never know what hit her." PIIHP by Brent September 24, 2005 0 0 Get merch Get the PIIHP mug. Buy Now — $32.95 See more merch