Slop.

Usually they respond to these accusations with ‘BUT I DIDNT SAY ANYTHING ABOUT GAYS!’

For me, the worst problem with sexual insults (aside from how obnoxiously high schoolish they sound) is that they rely on our culture’s stigmatization of sex to be effective. They simply don’t work if you see sexual favours merely as personal matters rather than phenomena that are somehow ‘inherently’ shameful.

I have never been into fellation. I would prefer not to see anybody either discuss or mention it on a regular basis. But employing it as an insolent metaphor should not make any sense, in the same way that nobody employs massages or assisted bathing as insolent metaphors. There are phenomena so much worse than fellating somebody, and employing it as a metaphor implies that merely aiding someone is neither serious nor shocking enough.