Machine Gun Kelly Says He 'Called It from the Beginning' with Travis Barker & Kourtney Kardashian

Machine Gun Kelly wants the world to know how long he's been championing Travis Barker and Kourtney Kardashian's relationship.

Following the Poosh founder and Blink-182 drummer's intimate wedding ceremony in Portofino, Italy, on Sunday, the pop-punker took to his Instagram Story to share a sweet video of the newlywed couple kissing on the dance floor during their reception, held at Castello Brown.

"okay y'all cute 🥰 @travisbarker @kourtneykardash," wrote MGK, 32, alongside the clip. "not gonna say i called it from the beginning but… 🤍💍🤞🏻"

MGK and fiancée Megan Fox, who respectively donned a blue leopard-print suit and a black liquid taffeta gown with a beaded corset bodice on tulle from Zuhair Murad's fall-winter 2021 collection, were among the A-list guests in attendance for Barker and Kardashian's nuptials.

During the ceremony, held at Dolce & Gabbana's L'Ulivetta grounds, Kardashian, 43, wore a custom white corseted mini-dress with a long, dramatic veil, and Barker, 46, sported a sleek black suit — both by Dolce & Gabbana.

For more on Kourtney Kardashian and Travis Barker's Italian wedding, listen below to our daily podcast PEOPLE Every Day.

The pair exchanged vows surrounded by red roses and loved ones, including their six total children: Kardashian's sons Mason, 12, and Reign, 7, and daughter Penelope, 9, and Barker's son Landon, 18, daughter Alabama, 16, and stepdaughter Atiana, 23.

A source close to the wedding told PEOPLE exclusively that Andrea Bocelli and his son Matteo were invited to perform. The musicians sang "I Found My Love in Portofino," "Can't Help Falling in Love" and their 2018 single "Fall on Me."

"It was an incredible moment and a very special performance," said the source.

Following the ceremony, Kardashian and Barker shared official wedding photos to Instagram, captioning their posts "happily ever after."

MGK's been publicly close to Barker since the pair collaborated on the rapper-turned-rocker's 2019 single "I Think I'm Okay" with YUNGBLUD. The acclaimed drummer then lent his production skills to the entirety of MGK's 2020 Tickets to My Downfall album as well as its follow-up, 2022's Mainstream Sellout.

Speaking to Nylon for a 2021 interview, MGK said witnessing Barker's artistic approach following his 2008 plane crash has been a major source of inspiration for him. "He showed me that I can attain a lot of the same highs that I search for elsewhere in music, because since his plane crash, he took the road to becoming sober," MGK told the outlet.

"And that never affects the way that his art came off, or how I look at him like he's a f—ing rock star, you know what I mean?" he continued. "He encouraged me to be in the studio and start to find highs in the music."

Elsewhere in the interview, MGK — who has a daughter, Casie, 13 — further detailed his bond with Barker and how their families have connected. "The times when we were working on [Tickets], and we'd be in there 'til 6 a.m. ... my daughter would sleepover with his kids, it was just kind of like a family support system going on to help us, you know, make that album," he said.

"We really bond as unconventional dads, and he's a great role model as a dad and made me want to become an even better father," MGK explained.