Alan's description of Emory as a "butterfly in heat" has to be one of the funniest lines of all time.
In any case, great performances all around, and it's ironic that the most stereotypical homosexual character (Emory) is played by one of the only straight actors in the cast (Cliff Gorman, better known for gangster and tough guy roles).
Around 15 years ago or so, I was leading a group discussion about internalized homophobia, and I decided to incorporate a performance of the two main Michael-Alan dialogue scenes into our discussion. I performed the role of Alan and another guy performed Michael. When I spoke that line about "He's like a butterfly in heat," the couple dozen or so guys listening to us perform all laughed uproariously.
I kind of wonder, though, whether a certain other bit of dialogue might be even funnier:
"I lost my grip doing chin-ups and feel on my heels and twisted my back."
"You shouldn't wear heels when you do chin-ups."
"I shouldn't do chin-ups; I've got a weak grip to begin with."
"A weak grip. In my day it used to be called a limp wrist."