Deal two cards down to each player. Bet.
From here out, whenever someone believes they have the highest hand, before the next card is dealt, they can declare Cheese Porn!. They put $1 into the pot. (This is not a bet.) The declaring person must have jacks or better.
If no one declares, deal another card to each player. Bet.
If you run out of cards (even if you complete the deal), all card dealt that round are discarded. Proceed to showdown.