The reality star-turned-TV presenter, 28, is currently in America's Sin City with family and friends having a blast before marrying Michelle Keegan later this month.
And he seemed chuffed to bits when he ended up behind the DJ booth as Calvin performed a set at Omnia nightclub. W-O-W!
Posing for a selfie, Mark looks ecstatic and tweeted: "Me and @CalvinHarris vegas baby !! Not only a legend but a LOVELY LOVELY MAN!!!!"
Mark also shared a few other snaps from his celebrations, telling fans: "VEGAS !!!! So much love!!!!"
And the former TOWIE star was man enough to admit that he's been "struggling" to keep up with the festivities.
Posing for a sleepy selfie, he wrote: "Power nap before we go AGAIN !! Vegas !!"
He also admitted: "Wow I'm struggling !! Have to try and get through this !! #vegas #1stag #onceinalifetime."
Mark has been joined on the trip by his best pals, including Kenzie and James 'Arg' Argent, and cousin Elliott and footballer brother Josh.
But while he's away partying before his upcoming nuptials, the loved-up star certainly hasn't forgotten his wife-to-be.
Thinking about fiancée Michelle, he gushed: "Being out in vegas is one thing but to keep me buzzing and smiling is knowing that in 2 weeks Im marrying the girls of my DREAMS. In and out."
He also responded to a cute tweet from none other than Cheryl Cole, who wrote: "@michkeegan is it just me or are you getting more beautiful by the day #glowing #happybridetobe @MarkWright_ you're a lucky man my friend."
Mark responded: "Oh @CherylOfficial dont I know it !! Luckiest man on the planet !! #mywife #itsdaysaway @michkeegan."
Stop it, you're making us go gooey!
Take a look at Mark and Michelle's romance:
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