Spencer Pratt Just Got Punk'd By A Siesta Key Cast Member

Kelsey is going undercover (prosthetics and all)

Spencer Pratt has some thoughts about Siesta Key and doesn't exactly have a filter when it comes to dishing his views about the Floridians. But what happens when the notorious Hills alum is asked questions by an MTV crew about certain cast members -- and one of them just happens to be standing right next to him in disguise?

In the clip below, Kelsey reveals that she's getting "a chin, a nose, a wig and a fake name," all with the hopes of catching Heidi Montag's hubby completely off guard. After he spills some tea, obviously.

"I got my full look ready," an unrecognizable Kelsey dishes from the studio, before Spencer arrives. "This is payback for all of the s**t you talk on me." We're getting shades of Ashton Kutcher's Punk'd days.

So what happens when Spencer dishes about Kelsey -- and how does he react when he learns she's been right by his side the entire time? Watch the hilarity ensue in the video, and don't miss Siesta Key (as well as Spencer's unrivaled take on the drama) every Monday at 10/9c.