(Full disclosure: I've never seen the movie, but have read numerous movie reviews of it. Also: In our modern culture, even someone who has never set foot in a cinema will unavoidably "soak up" some of this culture.)
My take is that it was not intended as a covert reference to fellatio. Rather, I think most kids would simply think that it was a "gross" thing to say - and they would say it for pure "shock effect," without any regard for any possible allusion.
But I agree that it is vulgar and does skirt the line.
Regards,
It is disgusting and at the time my kids did not say these things.
“My take is that it was not intended as a covert reference to fellatio.”
Well, then with all due respect, you’re very naive. Even as a 12-year-old, I knew it was intended as the slightly more creative equivalent of “c—k sucker.” If someone called you “garlic breath” or “cigarette breath” or “peanut butter breath,” it would refer to something that had been in your mouth.