Machine Gun Kelly Performs Emotional Song 'Lonely' During SNL Debut as Musical Guest

Megan Fox and Machine Gun Kelly Make Their Red Carpet Debut as a Couple at 2020 AMAs

Megan Fox and Machine Gun Kelly made their first major public appearance at the American Music Awards

Live from New York, it's Machine Gun Kelly!

The rapper and singer, 30, made his Saturday Night Live debut as the musical guest this weekend as the show returned for its first show of 2021.

For his first performance, he sang "My Ex's Best Friend," which he released in August 2020. Then for his final song, MGK performed "Lonely," an emotional track about his late father who died in July 2020.

Both hits are from his fifth album Tickets to My Downfall, which was released last September.

The show was also a first for host John Krasinski, who was previously scheduled to make his hosting debut last March before his appearance was canceled due to the coronavirus pandemic.

Will Heath/NBC/NBCU Photo Bank via Getty Images Machine Gun Kelly

Will Heath/NBC/NBCU Photo Bank via Getty Images Machine Gun Kelly

RELATED: Megan Fox Introduces Machine Gun Kelly's Performance During AMAs: 'We've All Been Under His Spell'

Just days before hitting the SNL stage, the musician sparked engagement rumors with girlfriend Megan Fox, who was in New York to support his SNL debut as musical guest.

On Thursday, the couple, who began dating last summer, were photographed together in New York City, with the actress, 34, wearing a massive ring on her left.

However, a source told PEOPLE that while Fox and Kelly are "very serious," they're not engaged.

Machine Gun Kelly/Instagram Machine Gun Kelly and Megan Fox

"There will be an engagement at some point, but they are not engaged now," said the source, going on to note that the actress is still in the process of finalizing her divorce from Brian Austin Green.

"Megan needs her divorce to be finalized before she can fully move on. She is very happy though," the source added.

The mother of three also seemed to deny the engagement rumors on Friday, posting a photo of a massive ring on her left ring finger with the words "F— You" written on it.

RELATED VIDEO: Megan Fox and Machine Gun Kelly Make Their Red Carpet Debut as a Couple at 2020 AMAs

Megan Fox and Machine Gun Kelly Make Their Red Carpet Debut as a Couple at 2020 AMAs

Megan Fox and Machine Gun Kelly made their first major public appearance at the American Music Awards

Fox and Kelly met on the set of their upcoming movie, Midnight in the Switchgrass and went Instagram official with their relationship last July.

Speaking to NYLON last November, the Jennifer's Body actress called her relationship with the musician a "once in a lifetime thing."

Sharing that they have a connection of "mythic proportions," Fox added that "loving him is like being in love with a tsunami or a forest fire."

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Opening up about their romance last year, Kelly said that he fell in love "for the first time" with Fox.

"That was my first experience with being open to love and stuff like that. I definitely wasn't set up to believe that that's something that could ever exist," he said during a September appearance on The Howard Stern Show.

Asked if it was love at first sight for them both, Kelly replied, "Yeah, for sure."