Supposedly, Grown Ups is a movie about five old friends who love each other very much. They're so completely unpleasant to one other, though, that it's hard to believe they get along at all. The guys—Lenny (Adam Sandler), Rob (Rob Schneider), Eric (Kevin James), Kurt (Chris Rock), and Marcus (David Spade)—gather to attend the funeral of their junior-high-school basketball coach. In one opening scene, Lenny greets Rob by trying to stick his finger up Rob's butt. At a funeral. Friendship!
After the funeral, the guys and their families spend the weekend together at a cabin, where the plot loses all coherence. There are too many people in the cabin—including, incredibly, Kurt's wife's mom!—and too many awful recurring gags. Someone gets an arrow in their foot, someone pees in public, a breast pump is put to unorthodox use, and all of it happens at least twice. There is one show of restraint: Marcus accidentally has sex with a dog, but he only does it once.
If Grown Ups has a unifying theme, it is how badly the "friends" treat each other. They make fun of Marcus for being single, Rob for his much older wife, and Eric for his still breast-feeding son. Lenny tells Kurt he looks like Michael Vick... if he were bulimic! Kurt tells Lenny he has a big butt... like Kim Kardashian! Then they all laugh at Rob for being too emotional about their beloved coach's death. This is the peak of their camaraderie. The guys only seem to laugh together, rather than at each other's expense, when Kurt's wife's mom farts loudly. Luckily for their friendship, this is the most recurring gag of all.
There are a few sweet family moments, but Grown Ups' pseudo-moral—that love sometimes breeds hostility—still comes off as delusional. The guys spend time together, and they pee in a public pool together, but they don't love each other. They just really love peeing.