The biggest balls I've seen in the flesh belong to my friend Josh. When first showing a room full of friends his balls, he simply lay on the couch, unzipped his pants, and pulled them out. He grabbed either side and pulled the skin out straight. Someone immediately exclaimed "Holy shit, dude. That's thing's so big that you could like..use it as a piece of paper to cheat on tests."
He calls it his "batwing."
During doggystyle, it feels really nice to have some big ol' balls slapping on my clit. lol *blush*