Your words belie your true thoughts

Say you’re celebrating the 21st birthday of another good friend of yours. You’ve gone to the house of his girlfriend, and you’re playing a board game you’ve never heard of (Sequence). You happen to be placed on the team with the girlfriend’s mother, who assures us that the game is easy to pick up. There’s a lull in the conversation. You feel like saying something.

What you do not say to her mother is "Well if she says it's easy, it must be".