Lady Gaga performs, discusses fiance on 'Jimmy Kimmel Live!'

Lady Gaga took to the stage on Jimmy Kimmel Live!

The singer and actress, 38, performed her song "Happy Mistake" during Tuesday's episode of the ABC late-night talk show.

"Happy Mistake" appears on Gaga's album Harlequin, released Friday. The album is a "companion album" to the upcoming film Joker: Folie i  Deux, starring Gaga and Joaquin Phoenix as the DC Comics characters Harley Quinn and the Joker.

Joker: Folie i  Deux opens in theaters Friday.

Gaga wore a clown-inspired outfit for her interview with Jimmy Kimmel. The singer discussed her fiance Michael Polansky, confirming the Minnesota native is totally "Minnesota nice."

Gaga also recalled how Polansky proposed at the end of a rock climbing expedition.

"He didn't propose to me at the top. We climbed up to the top and we looked around and we took some photos and then we went back down," the star said.

"He actually was very Michael. He asked me if he could ask me," she added. "He wanted to know if it was okay to propose before he proposed, and I was like, 'Yes! It's so okay.'"

Gaga said Polansky did not propose on one knee, adding, "I'm a modern lady. I like what he did."

Gaga confirmed her engagement to Polansky in June. The singer was previously engaged to actor Taylor Kinney and talent agent Christian Carino.