Zac Efron gets totally riled up in "Dirty Grandpa", thanks to his onscreen grandpa Robert De Niro. Maybe getting some fun back in Zac's life means that his girlfriend Sami Miro also gets to reap the benefit.

"Dirty Grandpa" trailer hit the Internet this week, showing the world that prudish Zac Efron got his world rocked by the veteran Robert De Niro. According to Out Magazine, the movie unfolds as "the pair ends up on some sort of grief-fueled bender that takes them to Daytona Beach for, what else, spring break. Cue the usual case of the grandparent trying to get the grandchild to lighten up and embrace his youth."

Seeing how there has been rumors that Zac Efron was itching to marry his girlfriend Sami Miro after filming "Neighbors 2", his character may not be so far from himself.

With all the rumors surrounding Zac Efron and Sami Miro, plus the fact that the actor loves to post about his girlfriend, the wedding bells may be ringing very soon!

According to Yidiba, "Zac Efron recently celebrated his 28th birthday with girlfriend Sami Miro. After dating for a year, multiple reports suggest that the two are thinking of taking their relationship to the next level."

Zac and Sami love being in each other's presence so much that they even do workouts together. By the looks of his body on "Dirty Grandpa" trailer, Zac Efron has definitely been benefiting from his model girlfriend's regime.

According to Daily Mail, "Efron continued to flaunt his sculpted stature on Tuesday as he performed some stunts in Atlanta, Georgia. Giving a new definition to 'smoking hot', the shirtless 27-year-old put on quite a show as he jumped over a fire pit while the cameras rolled."

Seeing how his girlfriend came to see him recently on set, the actor probably found another good reason to keep his body toned!