I'll try to write this as I continue crying while laughing. You nailed it! If those aren't all-time classics....

Of course it's hard to forget Groucho in "Duck Soup" or Steve Martin and Michael Caine in "Dirty Rotten Scoundrels".

Also, in the "Blazing Saddles" scene where Cleavon Little and Madeline Kahn are about to 'do the naughty', she switches off the light and says "Is it twoo what they say about...? Oh, it's twoo!" Cleavon's line was cut, where he responds: "I'm sorry to disillusion you ma'am but you're sucking on my arm."