IDENTITY THIEF
Near the very start of the Jason Bateman/Melissa McCarthy comedy Identity Thief, Bateman's character, the mild-mannered businessman Sandy Patterson, is enjoying a birthday party thrown by his wife (Amanda Peet) and two adorable daughters. After blowing out his birthday candles, Sandy scoops his younger daughter in the air - she looks about four or five - and, in what seems like a totally improvised gesture, turns her upside down, playfully plopping her face-first into the cake. The whole family laughs, but no one laughs harder than that cake-smeared little girl, who takes a second to wipe frosting from her eyes and mouth before exclaiming, to our utter delight, "Oh my God!"
Just thought I'd share that in case you were curious about the movie's funny moments, because for me, that was the only one.