It was on set that the two met and, according to Megan, she knew she was in trouble the second she found out he'd be in the film with her.
"I was like, 'Who is going to play this role?' And [Randall] was like, 'Oh, we just got Machine Gun Kelly,' and immediately, I was like, 'Uh oh,' because I knew," she explained. "I could feel that some wild shit was gonna happen to me from that meeting, but I wasn't yet sure what. I just felt it like, deep in my solar plexus that something was going to come from that."
MGK, real name Colson Baker, said the two had trailers on set situated right next to each other -- and he "waited" on his trailer steps every day, hoping "to catch one glimpse of eye contact" from Fox.
"There were like, five steps between the car and the door. And I would just sit there and hope and she would look over," he said. "She has the most gorgeous eyes I've ever seen."
Once they actually met face to face, the attraction was instant.
"The second I was in a room with him and said hello to him and looked into his eyes, I knew right away that he was what I call a twin flame," said Fox. "Instead of a soul mate, a twin flame is actually where a soul has ascended to a high enough level that it can be split into two different bodies at the same time. So we're actually two halves of the same soul, I think. And I said that to him almost immediately, because I felt it right away."
She said that on their second day working together, he joined her in her trailer for lunch -- where she proceeded to ask him "900,000 questions" pertaining to astrology.
"I went deep right away," she explained. "I knew before I even did his chart, I said to him, he has a Pisces moon. I could tell by his energy."
MGK added that all their initial conversations were "about the universe" and not necessarily how they felt about each other. Randall said he would also see a "huge synergy and energy" between them and felt their chemistry on set.
"There was a point where his character has to touch my hip," said Fox. "He put his hand on my hip and there was enough electricity to power like ..."
Before she could finish her thought, MGK interrupted, saying, "I'm surprised I didn't electrocute you or catch fire."
The foursome were also joined on the show by famed astrologer Susan Miller, who revealed what she saw in the cards for Fox and MGK as a couple.
"Your boyfriend, is he a writer?" asked Miller. "He's a musician," said Fox, as the astrologer said that's a "perfect" pair -- "the two of you are little money makers."
"Are you setting a date or is it a little early yet?" she then asked, getting a laugh out of Fox, who confirmed they are very much not engaged. That being said, Miller didn't see any "bad things" in his chart when it comes to marriage down the line.
"This looks good," she added. "You know how some marriages, the mate says, 'Why are you working all the time?' You would never have that problem."
Fox and ex Brian Austin Green announced their split in May, right around the time she was seen out with MGK.
"We've had an amazing relationship and I will always love her and I know she'll always love me," said Green at the time. The two share three children: Journey, 3, Bodhi, 6, and Noah, 7.
Of Fox's relationship with Kelly, he added, "I don't want people to think that [they] are villains or I was a victim in any way with any of this — because I wasn't. This isn't something new for us. This is something new for people to experience and hear about in the press ... but it's not new for us."