At which point a very blushing Zac admitted he's a proponent of prophylactics and that he found them to be "a great message" for the Dr. Seuss flick he's currently plugging.
Such the comic, that Zac.
So who's the funnyman using those condoms with and are they blushing alongside Efron?
"I don't think anybody's blushing and I don't think it's a whole bunch of people, if that's what you're wondering," said someone who's close enough to the 24-year-old star to know. "I can't say who, but it's not a lot of who's if you know what I mean."
Tastes aside, we're told by the Efron insider that Zac's lucky honey "isn't as famous" as Zac, which still leaves the cupid conundrum wide open.
Actually, all that statement really does is rule out Taylor and maybe even a rebound round with ex Vanessa Hudgens (as if!).
Hmm. Maybe the new Zac babe is slightly lesser-known Lily Collins Or…the lucky looker isn't even famous at all? That's our hunch.
What say you, celeb sleuths?