What's the worst/funniest argument you've ever heard for gay marriage?

The funniest/worst argument I've ever heard FOR gay marriage... that's a tricky one, but I thank you for encouraging me to think outside my perspective.

I think, perhaps, the argument that the Bible never says anything against homosexuality. Unless backed up by a valid interpretation, which it usually isn't, this betrays the speaker's ignorance of Christian scripture. If you want to debate someone's religion, at least do your homework. Know thine enemy, right? Not that Christians are my enemy... or even the enemy of gay marriage, for that matter. But you know, that's how the saying goes.

It's an interesting question, as there generally are few arguments for gay marriage that are free-standing arguments and not rebuttals/refutations of arguments against gay marriage. But there are a few.

The worst argument I've heard for gay marriage: "We just want to be treated like anyone else."

That's the worst argument (not just for gay marriage, either) for a couple of reasons:
1) It's semantically sloppy: what kind of treatment is meant? Medical treatment? Terms of address? There's a great episode of "Phineas and Ferb" wherein the evil mastermind who has conquered the city has passed a law that mandates that everyone is named "Joe". Nobody would actually want that, but it is explicit in the statement. So it's extremely unlikely that anyone wants to be treated like everyone else, but rather that they want the civil legal code to eliminate any distinction and/or requirement for gender in reference to marriage contracts.

2) It's syntactically inconsistent: By identifying a group as "we" the speaker is already making a distinction, which does not jibe with "treated like everybody else". For that to scan logically, it would have to be amended to something like "We just want to be treated like everyone else, while being recognized as distinct for the purposes of being identified as a separate group."

link

Cinders gave some awesome reasons+rebuttals here, a lot of which I heard in actual debate.

For marriage:

Note yourself that this was actually used by those who are against gay marriage...
"If we were to legalize gay marriage...our children would be taught a new way of thinking!"

xD
And that's negative how?

My friend said 'how will they have kids?'.

I said 'so can straight couples who can't/don't want to have kids not get married either?'.

The argument just makes no sense.

I heard this from a guy at my school:
"Think of it. Two penises? Two vaginas? Eew!"
That kid has a looong way to go.

"God hates fags"
and
"Eww gay people are morons they will go to hell"

I get mad even when I think of these, and I completely disagree with these close-minded people.

Hmm, there are many, but I thought this was rather funny and stupid: "But gay males get to go to the same public showers and saunas as heterosexual males! They just don't understand, how awkward it can feel when someone is watching your crotch and getting aroused. And there's nowhere to go on a public bath, when he sees your junk, the gay may already have gotten aroused, think of the young males who have to grow up like this!" or something to that effect.

Classic.

Gays are weirdos.

What kind of argument is that??