How Robin Williams Helped a Co-star Ask a Girl to Prom via AP Images

Ben Stiller and Williams teamed up to help Skyler Gisondo land a date — all while shooting the third 'Night at the Museum'

Skyler Gisondo didn't just get to work with two of his idols on Night at the Museum: Secret of the Tomb. He also got a prom date out of it.

Gisondo, who plays the son of Ben Stiller's character in the film, was a senior in high school during shooting. He was away from home, and his pals were also asking girls to the prom, so he decided to see if co-stars Stiller and Robin Williams would appear for a few seconds in a video to ask his prospective date.

Read more 'Night at the Museum' Stars, Director Remember Robin Williams 

"All morning, Robin was pitching more ideas," Gisondo tells 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!"

The video became more elaborate as Williams and Stiller continued to pitch ideas.

"It turned into this three-minute, ridiculous thing. A prom-posal," says Gisondo. "I realized that was the most awesome three minutes of my life and I've accepted it will go downhill from there."

Read more 'Night at the Museum: Secret of the Tomb': Film Review

The video landed Gisondo the prom date.

Gisondo is also set to appear in the Vacation reboot for next year.

"It's a continuation of the original Vacation, but in many ways it's a whole new monster," he says. "[Stars] Ed Helms and Christina Applegate just complement each other so well. Every castmember fit into their roles so perfectly. It was great to be a part of this cinematic family."

The actor says his time working with Williams, who died Aug. 11, was "invaluable."

"Robin was this bottomless reservoir of kindness and hilarity," says Gisondo. "It was juts so special to work so closely with this guy who's movies I've grown up with and watch his preparedness and his kindness."