Nothing in a game of D&D has ever made me question my friends' intelligence like the time he was a lawful stupid paladin, and I was a chaotic evil pathological liar with a literal god-like power to not just use deception in a realistic way, but would magically make any lie that succeeded fully believed by the affected individual. I basically could only lose a sense motive check against me if I rolled a 1. Paladin player can see my character sheet since it's all on the Roll20 system in game attached to my token, and there is no possible way he could ever win a sense motive check against me; but he would still try every. Damn. Time. My character would speak. It wasn't even the metagaming that annoyed me at that point. It was the lunacy.