Las Vegas, Nevada - Machine Gun Kelly and Megan Fox debuted matching ring finger tattoos in honor of the Transformers star's 36th birthday.

After MGK set off plenty of rumors about the couple during his rocking performance at Sunday's Billboard Music Awards (BBMA), the engaged pair hosted a star-studded bday bash for Fox.

The birthday girl swapped out of her red carpet attire for the epic party, where she sported a strapless sequined gold dress and silver tiara.

Meanwhile, her soon-to-be hubby was seen still wearing his dramatic spiked Dolce & Gabbana suit, a look he dubbed "emo cactus."

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A few big names attended the party, including Diddy, Mary J. Blige, Usher, Heidi Klum, Lil' Kim, Teyana Taylor, French Montana, City Girls, and Alex Rodriguez.

But Fox's bday celebrations didn't end there.

On Tuesday, in a moving birthday tribute to his future bride on Instagram, MGK also debuted matching finger tattoos he got with Fox.

"Wishing the happiest birthday to my ethereal light being. I love you maki," he wrote under a photo dump that included voodoo doll tattoos, characters from Pixar’s movie Up, and the couple in matching blue outfits.

Notably, the pair got the ink on their ring fingers. And after MGK dedicated his BBMAs performance to his "wife" – did the two pull a Kravis and secretly wed under our noses?

We're still waiting on some clarification.