Pete Davidson & Machine Gun Kelly Down for a Buddy Comedy

Pete Davidson and Machine Gun Kelly have a movie together playing at Sundance, but as for having a classic buddy comedy in the works? Well, they didn't say no.

We got the real-life pals at the Sundance Film Festival in Park City, UT Monday, where their new dramedy, "Big Time Adolescence," is debuting this week. Our photog wanted to know if they'd ever star in a buddy movie, like Vaughn and Favreau.

Pete and MGK got giddy at the prospect ... Pete voiced approval, "Hell yeah!!!" Hey ... they've already collabed together, so they're well on their way.

Check out how they spent their time getting to Utah ... Pete and Kelly are always good times, even when life hurts.

Shoot, even when we tried asking Pete something serious about his rocky year, he went all pie-zano on us.

We're no chemistry teachers, but we think Vince and Jon would be seriously proud.