Charles Barkley is no longer a gambler, if you believe the things that he says. (I, um, do not.) But that doesn't mean he can't go out drinking in Las Vegas, hang out with a professional poker player and then get conned into playing a game of H.O.R.S.E. And, of course, it most certainly doesn't mean that he can't airball two shots in said game en route to being embarrassed by a guy who plays cards for a living.
But hey, Charles, don't worry about it. You're just one of the 50 Greatest NBA Players of All Time and a guy who wants to run for Gov. of Alabama. This seems like totally appropriate behavior.