Dirty Johnny's mom is in the kitchen cooking dinner...

Johnny runs up to her, tugs on the tails of her skirt--
"Momma, are we having shrimp for dinner?"
She tells him, "No, Johnny, we're having meatloaf."
Johnny says, "Oh. Well, Grandma's having shrimp!"
"What do you mean Grandma's having shrimp?"

So Johnny takes his mom's hand, leads her into the living room-- and there's Grandma on the couch.
She's sleeping like a rock, lit cigarette in her mouth, and her bathrobe's slumped off to the side to reveal her gnarled old lady clit

Johnny points at it and goes, "Look, see, it's Grandma's shrimp!"
Johnny's mom, horrified, puts her face in her hands and says,
"No, Johhny, that's not shrimp, that's Grandma's clitoris."

Johnny says, "Oh.. Well, it tasted like shrimp!"

WACKIDYYY-SHMACKIDY DOOOOOO

(Courtesy of Jackie 'The Joke Man' Martling)