some fellows are sitting in a bar, when an old man decides he doesn't like the look of one of them, so he goes up to the young man, (who is just trying to drink his beer, ) and taps him on the shoulder.
"your grandmother is the best sex in town!" he shouts.
the young man looks uncomfortable, and attempts to ignore the old guy, who blinks waiting for a reaction. when he gets none, he stumbles back to his stool, and sits there, glowering for a few minutes, until he thinks of a new insult, when he thinks of one, he regroups and tries again, wandering over to the young man once more...
"i just had sex with your grandmother, and ohhh! it was sweeeet! what do you think of that?"
the young man says: "i think we should go home grandpa, you've had enough."