While performing anal sex, you pull your dick out and drop several "just-add-water" foam expanding dinosaur capsules in her asshole. Then reinsert, pee in her butt and wait. Some of the dinosaurs will flow out when you're done. The others will stay in there for a while and give your wife/girlfriend a nice surprise the next time she TRIES to drop a deuce.
My girlfriend gave me anal for my birthday.
I gave her a jurassic waterslide for being a bitch all year.
I gave her a jurassic waterslide for being a bitch all year.
by MagicRat April 19, 2018

When you are having sex and the penis slips out of the vagina while on the "backstroke" and you thrust forward and the penis forcefully enters the anus.
by theunderwaterhamburgler September 5, 2022

When you have sexual intercorse with a minor and she squirts all over your treasure trail right down to your ass hole
by balius September 14, 2010

When you go down an steep waterslide and the water is forced up your butthole and gives you an unwanted enema.
When at the waterpark I like to watch the women at the end of the steep slide, they pull their bathing suit bottom from the crack of their ass and then you see water run out of their ass. “Did you see her waterslide enema flow out of her?”
by NYPussyvore December 16, 2023
