Donald Trump commits golf's 'unforgivable' sin

There's a lot of things you can do on a golf course that, while may not defy golf's etiquette, are very much within the laws of the game. Swearing, shouting, slamming clubs; it all happens occasionally. But what President Donald Trump just did, as any golf fan will tell you, is a step too far.

Granted, Trump did it at the golf course he owns, so in reality he can do whatever he wants, but even still: Driving a golf cart on the putting green? Ruining that impeccably-manicured putting surface? So rude.

Golf fans, naturally, were outraged about it.