Fox had a lot of love for her boyfriend's first-ever time as an 'SNL' musical guest.
Fox took to Instagram on Sunday to share a trio of snapshots showing herself and her rocker boyfriend outside 30 Rockefeller Center in New York, during the past "SNL week" -- meaning the last few days as Kelly rehearsed for his set.
Fox had some high praise for Kelly's appearance on the episode, calling it the "best performance that show has ever seen 🤯💔"
On Saturday, Kelly took the Studio 8H stage for his first performance of the night and belted out his hit "My Ex’s Best Friend."
Kelly went full rock star during his first set, stepping (and almost stumbling) over amps while playing and finally throwing his bright pink electric guitar into what appeared to be the audience or the wings of the stage after the tune was done.
Kelly's second performance really showed the range of his style and substance, as he delivered a remarkably beautiful and emotional performance of his song "Lonely."
The song struck a cord with many fans, given the significance of the tune's lyrics in relation to his father's death in July 2020.
Kelly's performances on SNL came two days after the couple sparked engagement rumors when Fox, 34, was spotted wearing a ring on that finger outside a hotel in New York City.
Fox seemingly replied to the rumors with an Instagram Story photo posted shortly thereafter, which included a shot of her left hand with a ring that reads, "F**k you."
A source told ET in December that Kelly "totally sees marriage in his future with Megan and friends could 100 percent see them getting engaged within the next year."
However, the source noted that Fox "doesn’t think about getting engaged [or] married and she doesn’t put a timeline in place and it’s not something that really crosses her mind."
Whether or not they're ready to take the next step, the source said that the couple has a "strong connection."
"MGK and Megan lean on each other emotionally and both understand one another because of their strong connection and because they are both parents," the source said.
Check out the video below to hear more on Kelly's first-ever SNL gig.