Best definition
Water Ballooned
The act of urinating during anal sex. Like filling a balloon with a garden hose.

“I picked up this chick from the bar and I totally water ballooned her by accident!”
Water Ballooned: define #2
Water Ballooned
When you wrap up and, mid smash, wait to get just soft enough to piss into the condom. Fill it up. Slyly withdrawal, pinching and tying off the “balloon”. Run.
Ah shit man, I dont think I’m coming to the party.

Why not?

I water ballooned Marika last weekend, not sure if she ever got it out after. Either way, she’s gonna be pissed.