Rules dealing w/ those who show their hands early.

[wacki]

I run a regular home game that meets atleast once a week. I've never seen this happen at a casino, so I don't know how to deal with it.

What are your favorite rules for dealing with someone that shows their hand (or one card) too early?

Basically I'm trying to find out what the best rules are and stick them into my homegame.

Please don't hassle me about giving up money by adding rules into my homegame. If I want to make $ I'll go to a casino. This is to avoid conflict in a friendly home game that normally has a few randoms.