Adam is standing there, pants around his ankles, his tighty whiteys becoming increasingly transparent, not too mention starting to get heavy, and everytime he tried to pull his pants up, he was met with a blast of water to his face, so he decided to try to run past his brother and pull his pants up at the same time, he was always pretty fast.
He looks over at Nicki and sees her laughing hysterically at him, and squirting him with his own squirt gun, then looks at his brother who is still spraying away, and laughing, so Adam makes his move, he turns away from his brother so when he bends down to pull his pants up, he can't be sprayed in the face (his brother instead aims right for his butt causing his tighty whiteys to fall slightly exposing about a half inch of butt...to the delight of both Nicki and Kevin), Adam pulls his pants up slightly and while still trying to pull them up, turns around to run towards the stairs to the deck and....
SPLAT! he falls face first on the ground...because he just tried to run...with his pants around his ankles
Nicki literally falls over shes laughing so hard, as Adam landed with his butt in the air, and to make it even better (in her opinion anyways) the force of the fall caused his tighty whiteys to fall down even further leaving his entire butt exposed, also one of his shoes fell off, Kevin actually stops spraying Adam for a second cause he is laughing too hard at what just happened.
Humiliated Adam pulls his underwear back up recovering his butt and at least some of his dignity, Kevin started to spray him again, Adam started to get back up, and got blasted in the face again, one shoe was gone, and because his pants had fallen completely off of one leg, the other leg they were still bunched up around his ankles, so now he could try to put them back on, with two people laughing at him, and hope they let him do so in peace (not likely) or he could just take them all the way off and run inside the house pantsless...still embarrassing, but better than getting stripped by water, he made his choice and...