*the kissing distracts killua so thoroughly that he doesn't realize how far he's built up until he's almost there and an involuntarily jerk of his hips snaps him back to reality. breaking contact with gon's mouth, he mumbles:*

mmmn- i'm close. can this thing even...?

*he gets his answer a moment later when the squirming organ stiffens in gon's fist, spurting out much more liquid than a human could and splattering them both with watery spend. killua gives a strangled yowl, thrashing like a caught fish on the rocks in a combination of mortification and ecstasy.*