Zac Efron Asks Robert De Niro to Wish Sami Miro a Happy Birthday - Watch Now!

Zac Efron asks Robert De Niro for a huge favor in this hilarious new Funny or Die video.

The 28-year-old hottie asks his Dirty Grandpa co-star to wish his girlfriend Sami Miro a happy birthday.

Robert obliges, but his mundane “happy birthday” doesn’t really suffice for Zac. He asks him to try again with more energy and maybe some balloons.

It doesn’t go so well. Watch Bob tell them off in the video below!

“Oh my God, you better love that,” Zac tells Sami.