Fox first mentioned the tattoo in MGK's Tickets To My Downfall, speaking in the track "Banyan Tree (Interlude)."
"It was just four months ago that we were right here and I met you. That's not possible," Megan says in the song. "You just got my initials tattooed on you. I just got your nickname tattooed on me."
Fox's voiceover wasn't her only impact on the album and the singer.
MGK told Howard Stern in September: "After I made... the big chunk of the album, I did fall in love for the first time. It 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."
The tattoo in question the Spanish word "el pistolero" in a delicate script under her collarbone. "El pistolero" is Spanish for "the gunman," one of Kelly's nicknames.
Check out Fox's latest tattoo here!
MGK also got a tattoo in honor of Fox though we don't have the details on it just yet.
However, back in July, the tattoo artist behind Megan Fox and MGK's romantic tattoos did share a video of their tattoo session (though it did not include any final results).