Waterparty Share definition Flag When you poop out a big one and the water splashes back into your anus. I was shitting real hard when I suddenly felt this cold feeling in my ass, I think it was a waterparty. Waterparty by Stokke ( ͡° ͜ʖ ͡°) May 5, 2016 0 0 Get merch Get the Waterparty mug. Buy Now — $32.95 See more merch