This one isn't a strictly Fry-and-Laurie entry; it's from the 1982 Cambridge Footlights Revue, but it has Emma Thompson and Stephen Fry trying to out-U one another, and that is a rare gift and a shining jewel.
"My darling, you're looking pale."
"I am pale."
"Oh, my darling, don't say that, don't even think it."