Zac Efron manhandles a penis in seriously explicit 'Dirty Grandpa' scene

Just in case the sight of Zac Efron going totally naked in the trailer for his recent comedy outing with Robert De Niro, Dirty Grandpa, wasn't enough to persuade you of the film's in cinematic history, new stills showing the 28-year-old star coming face-to-face with a penis in one of the movie's more raunchy moments may do just that. The film sees Efron play uptight lawyer Jason Kelly, whose road trip with his newly-widowed grandfather (De Niro) takes several turns for the worst after his aging relative decides to embrace his single status and engage in some seriously debauched behaviour. And while its already proven its got plenty to offer in the Zac Efron nudity stakes, new GIFs circulating online capture the moment the former High School Musical star comes into contact with someone else's - quite literally. zac 01 While we sadly can't show the undoctored images (believe us, we're distraught), the stills below should give you some idea of just how 'hands-on' Zac's role was. We can only assume that the manhood in questions was a prosthetics one, but that certainly doesn't spoil the illusion... zac 02 zac 5 zac3 zac 6 zac 4 More stories: Picture special: Zac Efron cops a feel on set of ‘Bad Neighbours 2’ Zac Efron's manhood described in glorious detail by co-star Adam Devine Watch | Zac Efron shows off his manhood in new viral clip