Hang on, hang on.
Is not the joke (a) a reference to MacGruber's homophobia (poking fun at it, not an endorsement of it), and (b) more evidence of MacGruber's obvious sublimation and denial of his own homoerotic impulses? I mean, why does he constantly offer to, you know, "suck" things when he's in trouble?
This is a deep, deep film, Bondo.