I was playing a game of Settlers of Catan the other day and one of my fellow players rolled a seven. One of the other players was trying to convince the person who rolled seven to put the robber on me, because he thought I had a resource that I didn't. So I showed everyone my hand to prove I didn't have it. Then, the player who rolled seven placed the robber on a different player and a huge argument broke out.
I've lost my rule book, so I'm asking: is showing your resource cards like this cheating?