Friday, Machine Gun Kelly made an appearance on The Late Late Show with James Corden to perform with “Emo Girl” with Willow Smith.

He also chatted with the host, saying he and Fox have very clear ideas about certain wedding set pieces that might be difficult to actually execute. After Corden asked when the wedding was planned for, MGK said he was “trying to find a spot” that worked for his “artistic” vision of the ceremony and reception. The couple wants to have a “red river” and “gothic” features, so naturally the “location is hard.”

He hasn't quite worked it out and things may shift.

“I change my opinions about things a lot,” MGK explained.

The pair is great at doing themed events. This week, they attended the Avril Lavigne concert at The Roxy Theatre in West Hollywood together dressed in a matching classic pop punk style. Machine Gun Kelly's song with Lavigne was co-produced by hi friend Travis Barker, who was also in attendance with his fiancée Kourtney Kardashian. The musician took to the stage to perform “Bois Lie,” the second track on her new album Love Sux.

MGK also congratulated Lavigne on her new album on Twitter, writing, “congrats on the album @AvrilLavigne !! i can’t believe i’m on it, Bois Lie was so fun to record — video soon.”

Fox and MGK met in 2020 while on the set of Midnight in the Switchgrass. Fox appeared in a music video for Machine Gun Kelly soon after and they got engaged in Puerto Rico. Fox has three children with her ex husband, actor Brian Austin Green.