In "Neighbors," Zac Efron's fratastic alter ego spent an exorbitant amount of his Delta Psi presidency term tormenting his next-door neighbors who were legit just trying to let their baby catch some zzzz's. He was a senior jackwad, in other words.

But IRL it looks like Seth Rogen is the one who's doling out the punishment on the Zefron.

Keeping us up to date on the latest set shenanigans from "Neighbors 2: Sorority Rising" -- for which we thank you, sir -- Zac dutifully posted an Instagram picture of his relatively playful hot dog-inspired jab at Seth, capping this pic with "I really need to talk to you about this scene dog."

First of all, we totally suspect that this is the most PG-rated thing you'll ever see from this movie, and secondly, HA! We see what you did there, Z.

But it looks like Seth didn't find this big hot dog/small hot dog innuendo business funny at all because the very next encounter involved a few F-bombs being slung in Zac's direction by both Seth and the still creepily clowned up Ike Barinholtz.

Poor kid. They're so meeeeean.

JK JK. Zac's in on it here, obvi.

In fact, he seems to be having the best time ever on the set of "Neighbors 2" right now -- and not just because of the fact that it's his first sequel ever outside of the "High School Musical" sphere.

He also gets to chill on top of endangered pintos.

And work on his core outdoors.

Also, he's got plenty of spare time for, um, adjustments.