Guys not showing both cards, flipping cards onto community cards.

[TomBrooks]

I was in a home game that just had it's second monthly game.

At showdown, some guys were showing only one card.

Some were flipping one or sometimes both of their cards on top of the community cards, presumably to better illustrate which cards matched up to make a hand.

I'm new to live poker and it shows because I'm not used to following live action so I don't have the image as an expert at this game. However, I tried saying some things about not doing these practices but with only a little success.

The guy running the game is new to poker except for an annual Christmas tournament he ran for friends and family for the last few years. It was my idea to him to run a monthly game because he has the room to do it.

I don't like guys flipping their cards around at showdown. What would you do?