12/23/2014 12:19 pm ET Updated Dec 31, 2014

Robin Williams Hilariously Helped His Costar Ask A Girl To Prom

Skyler Gisondo is like a lot of teens who want to go the extra mile in asking someone to the prom. Only he had Robin Williams, Ben Stiller and a monkey to help him.

Who's gonna say no to that?

Gisondo, an 18-year-old actor, was shooting "Night at the Museum: Secret of the Tomb" in May, which is smackdab in prom season. So he asked his comedic costars Williams and Stiller to help him make a "promposal" video.

Williams being Williams, he turned what could have been just a polite quick favor for a colleague into a heartfelt project -- juiced with plenty of zaniness of course. Here's the video in full:

All morning, Robin was pitching more ideas,” Gisondo told The Hollywood Reporter. "He was saying ‘Can I say this? Would it be appropriate to say this?’ You’re Robin Williams. You can say whatever you want!”

His prospective date said yes, by the way -- and Gisondo came away with even more reverence for Williams, who was found dead months later.

At the the film's recent premiere, Gisondo told E! in the segment above that the "promposal" was "the highlight of my life."

H/T Uproxx