Robert De Niro Got Weird with Zac Efron and Stuck His Finger Up His Butt on Set of ‘Dirty Grandpa’

at 12:50 pm | By

You might have thought you’ve seen it all when Zac Efron was spotted in a Coachella-inspired crop top and, of course, nearly-naked in nude briefs on the set of Dirty Grandpa (because that butt, right?). Nope. Wrong.

Alas, we’re not sure what’s going on in Dirty Grandpa but it may or may not have called for Efron’s co-star Robert De Niro sticking his finger up his butt while he was clad in a questionable-looking pair of mustard yellow pants.

Lucky for you, we’ve got pictures!

Robert De Niro sticks his thumb up Zac Efron's butt while filming scenes for Dirty Grandpa

There’s obviously a lot of hijinks going on with the boys on set, and we won’t really know what the point of De Niro having his finger up Efron’s butt is ’til the movie comes out on August 12, 2016.

So until then, please enjoy some of these GIFs of Efron’s fit and fun body just for you, and check out the shenanigans in the gallery above!