Similar to "docking" where after touching heads, one uncircumcised homo puts his foreskin over the other fuckin homo's head and pisses thus creating the "water balloon" effect.
Ben managed to keep the sheets dry, until his pathetic cock's water ballooning seal broke ans his water balloonexploded all over Mike's bed.
Is when a man with an uncurcumcised penis pulls his foreskin to the top of his penis to shape a little area to store urine and or semen, usually filling the area up with urine, until it eventually bursts like a water balloon
Man 1: Yea man I tried that water ballooning thing you told me about and got piss all over my sink
Man 2: wow dude you actually tried water ballooning?