A dusty cowboy rides up to the saloon on his horse, gets off and ties it to the hitching post, then slaps the dust off his jacket and chaps. He walks around to the back of the horse, puckers up his lips and kisses the horse directly on the asshole. He then walks into the saloon, walks up to the bar and says to the bartender "Whiskey!"
The bartender pours him a glass of whiskey and says to the cowpoke "Say there pardner, I noticed when you got off your horse you went behind it and kissed it right on the asshole. Why'd you do that?"
The cowpoke replies "Chapped lips."
"Chapped lips?" asks the bartender, "Is that a cure for chapped lips?" "No" says the cowpoke, "but it sure's hell stops you from lickin' 'em."