In the movie Lucky You, when Huck and his father are playing cards in the diner, what game are they playing?

It seemed like Guts, but I've never seen it played where the players don't declare they are in simultaneously. Can someone point me to a how to play site?





Thanks!

In the movie Lucky You, when Huck and his father are playing cards in the diner, what game are they playing?
poker

choose roller blades