Meet Zac Efron's real-life neighbor: 'It's Always Sunny in Philadelphia's' Charlie Day

zac-efron-charlie-day-are-neighbors.jpg Zac Efron is currently dominating the box office with Seth Rogen in "Neighbors," the frat vs. family raunchy comedy that plays to both Efron's and Rogen's strengths.

Namely, there's a bunch of penis jokes, a whole lot of pot and Efron spends most of the movie shirtless, with his shirt hanging open or in a tight muscle tee. And hey, it works!

But Efron took the funny to Instagram on Friday (May 16) to show off his real-life neighbor, "It's Always Sunny in Philadelphia" star Charlie Day, and the antics he deals with on a daily basis.

Check out Efron's hilarious video below:

Photo/Video credit: Getty Images/Instagram