Go to the scene where the couples are playing Pictionary and Meg is drawing a picture of a baby.
Later, after they are finished playing the game it shows the drawing in the background and it is completely different from the one that Meg drew earlier.
Actually, (after watching this movie many, many times) it is clear that the Pictionary scene is spliced from at least four different takes. There are four different baby pictures (pay attention to the mouth and eyes; sometimes the mouth or eyes are circles, sometimes they are lines). Yes...I've watched this movie WAY too many times.