Anything Slim

 

In Season 8, Episode 15 (production code 4F11) of The Simpsons, Homer's worried Bart is gay, so he sits him in front of a billboard portraying a sexy lady pillowfight for a few hours to straighten him out. The billboard is advertising Laramie Slims, a cigarette marketed towards women, but Homer's just hoping Bart becomes attracted to the women. When he returns, they share this exchange:

Homer: "How do you feel?"
Bart: "I dunno, kinda want a cigarette."
H: "That's a good start. Let's get you a pack. What's your brand?"
B: "Anything slim!"
H: *Annoyed groan* "Okay, that didn't work."

How did Homer know it didn't work? At first he just accepted that his 10 year old son wanted a cigarette, so was it the word 'slim' that brought the connection to the billboard to his mind? Is that what made him realise Bart missed the point? That's one theory, that Bart accepted the cigarettes into his mind instead of the ladies, but let's consider some other explanations.

For most of my life, from my initial understanding of the scene, I held the belief that Homer was parsing Bart's phrasing as some kind of reference to gay culture, or something similar. Drawing on the stereotype that gay men are slim, maybe Homer thought Bart was using a double entendre to allude to his sexuality. Nowadays I don't think this makes much sense, but it's still possible as a solution.

Another theory I find plausible but that I think gives Homer too much credit is that Bart's remark that he'll accept "anything slim" makes Homer realise that the billboard hasn't had any effect at all. In asking "What's your brand?", Homer's hoping Bart will ask for Laramie cigarettes; if Bart took on board the marketing, maybe he'll have been subliminally implanted with Homer's intended message, too. This makes sense, since he finds it promising that Bart brings up wanting a cigarette, but Homer's plan is defeated when Bart doesn't mention the targeted brand at all.

Finally, there's the idea that since Laramie Slims are marketed towards women, Bart wanting one, or any slim brand at all, means he's effeminate and therefore gay.

If there's an official answer to this question, I can't find it, and any summaries or references to the scene don't give any explanation at all, at best just mentioning that Homer figured out it didn't work from what Bart said. Maybe it's obvious, but I've come up with so many good explanations that I'm not sure which the obvious one would be. Maybe you can tell me.