Jason Aldean is engaged to his former mistress Brittany Kerr, the country superstar's rep confirms to Us Weekly Credit: Rick Diamond/Getty Images for CMT

Lockin' it down! Jason Aldean is engaged to his girlfriend Brittany Kerr, the country superstar's rep confirms to Us Weekly.

The "Burnin' It Down" singer and former American Idol contestant celebrated their engagement news at the San Diego Zoo on Wednesday, Sept. 24.

Kerr shared an Instagram photo of herself feeding a sea lion on Thursday, captioning the pic: "My man did it again. Today was amazing."

Aldean's surprise proposal coincides with his latest Billboard magazine interview, in which he demanded people move on from the extramarital affair that began his relationship with Kerr. "It has been two years of this s---," Aldean, 37, said of his cheating scandal. "Get over it, already! And then when I finally do get enough of it and say something, every newspaper grabs it. And I'm not trying to get in the headlines — I'm just trying to get people to stop running their mouths."

In September 2012, Aldean was caught kissing Kerr in a Hollywood bar while he was still married to his wife of 12 years, Jessica Ussery. Though he attempted to repair his marriage to Ussery, with whom he shares two little girls, Keeley, 11, and Kendyl, 6, Aldean ultimately filed for divorce in April 2013.

Kerr made her first red carpet appearance alongside Aldean this past June, when she controversially accompanied him to the 2014 CMT Awards in Nashville.

After enduring backlash for bringing her to the event, Aldean took to social to defend his relationship with Kerr. "So sick of people judging me and @brittanylkerr over things they know nothing about," he wrote on Instagram in July. "I have made mistakes but i am a better person because of it, and wouldnt change a thing. Im happier than i have ever been, so thank u to all the people who support us. We are happy and life goes on. Its time to move on people."

This will be the second marriage for Aldean and the first for Kerr.