"Sorry, mom," he says after the camera has panned up to reveal his outfit.
Speaking about the comedic value of embarrassing Efron on and off camera, his co-star Seth Rogen told Haute Living magazine, "We tend to be mean to Zac." He explained, "No one is sympathetic to Zac Efron. He's so handsome."
After making the High School Musical star the butt of some slapstick comedy in 2014's Neighbors, Rogen learned how to get laughs from making the handsome guy squirm.
"All comedy comes from making him experience pain in some way – that's what we've found out," he joked.
Neighbours 2: Sorority Rising also stars Chloë Grace Moretz, Selena Gomez and Rose Byrne. It hits theatres May 20.