The musician teased what he's envisioning for their big day while walking the red carpet at the 2022 Billboard Music Awards on May 15.
"I don't want to say too much," he exclusively told E! News outside of the MGM Grand Garden Arena in Las Vegas. "It's going to be weird. It's going to be completely out of the box."
So what does Megan think of his ideas? "She's a genius," MGK, who popped the question in January, continued. "You know what I'll say? I'll throw the reel out really far, and then she'll reel it back in if it's too far."
For now, the actress, 36, and the "Bloody Valentine" artist, 32, are focusing on the BBMAs. The couple arrived in chic ensembles, with Megan wearing a black David Koma dress and Machine Gun Kelly donning a Dolce & Gabbana suit. MGK received a nomination in the Top Rock Artist category and is one of several stars set to perform.
But what about their plans for after the show? It is Las Vegas, after all, and some couples have finished off an awards show night with a trip to a wedding chapel. Joe Jonas and Sophie Turner tied the knot in Sin City after the 2019 Billboard Music Awards and Kourtney Kardashian and Travis Barker had a ceremony following the 2022 Grammys (while Kravis' Las Vegas wedding wasn't official because they hadn't obtained a marriage license, two sources tell E! News Kourtney and Travis have now legally wed and tied the knot in Santa Barbara, Calif on May 15).
So would Megan and Machine Gun Kelly be up for practicing saying their "I dos"? It doesn't look like it as they'll be busy celebrating Megan's birthday.
"Well, it's my fiancée's birthday at midnight," MGK said. "So, we're celebrating her wonderful life being here on planet earth."
To see more couples at the 2022 Billboard Music Awards, click here.