The 34-year-old actress and the 'Rap Devil' star have been in a relationship since May this year, and Kelly has admitted he had no idea true love actually existed until he fell head over heels with Megan.
Speaking on 'The Howard Stern Show', he said: ''I didn't know what [love] was until me and her made eye contact.
''That's when I was like, 'Whoa.'
''After I made the big chunk of the album ['Tickets to My Downfall'], I did fall in love for the first time.
''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.''
When Howard asked if it was love at first sight, Kelly - whose real name is Colson Baker - replied: ''Yeah, for sure.''
Since dating the high-profile actress, the 30-year-old rapper has had paparazzi outside his house every day, which he admitted is the only ''problem'' of the relationship.
He said: ''My house isn't gated, so that's the one problem. Everyone knows where my house is, so it's like this odd moment, where I was kind of living my life super normal and the next day, there were paparazzi outside my house every day.''
Should the pair tie the knot, Kelly would love for his close friend Pete Davidson to be his best man.
When the host suggested the idea, he said: ''That's cool. Yeah, I'm down with that.''
The couple seem serious about their relationship, as Megan has already introduced her beau to her sons Noah, seven, Bodhi, six, and Journey, four, whom she has with her estranged husband Brian Austin Green.
Megan announced her split with Brian shortly before going public with Kelly and was reported that the 'BH90210' star is ''protective'' of his brood.
A source said: ''MGK has met Megan's kids, but Brian is pretty protective of them. Megan and Brian's relationship is so up and down. They have been coparenting in a healthy way as best as they can.''
The insider also insisted Megan and Kelly - who has 12-year-old daughter Casie from a previous relationship - are nowhere near discussing the next stages of their romance such as marriage or having kids of their own, but are definitely ''obsessed'' with each other.
They added: ''MGK and Megan aren't seriously talking about getting engaged, married or having kids right now and they're not there yet. It's too soon for everyone, both of their kids and Brian [Austin Green] included. They are definitely super into each other. MGK is obsessed with Megan.''
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