Right, remembered, christ my brain is slow.
Scene - the Toga party in the Delta House. A guitar player is serenading some toga clad ladies at the foot of the stairs.
John Belushi (Bluto) appears at the top of the stairs, wearing a toga. He seems to be intently listening to the guitarist.
Then, as he moves down the stairs, he grabs the guitar and smashes it to pieces against the wall and the stairs.
He then hands the guitar back to the player, shrugs and says Sorry
