Coach

Player 1: Why isn't Dave at practice?
Coach: He has 3 tests tomorrow so he needed to spend time studying for them.
Player 1: He is such a liar! I saw him today and he said he was going home to sleep and was just being lazy.
Coach: He just lies to you so that he can seem cool. In reality, he is actually studying.
Player 2: You're wrong coach. I haven't told you the truth all year. So that means he's lying.

(Dave is a fictional name)