1. It was nice chatting with you. 2. Well, it's getting late. 3. Anyway, I should get going. 4. (formal) Sorry, but I'm afraid I need to... 5. I'm sorry to cut you off, but I actually gotta run. (cut you off = interrupt you)
If a player draws fewer tiles for his hand than he is entitled to, it is called an underdraw. Once an underdraw has been discovered, he draws the necessary tiles from the stock to complete his hand.