Just a few hours after the two walked the red carpet and attended the Billboard Music Awards on Wednesday night, the lovebirds headed to a local chapel in Sin City to tie the knot. ET exclusively spoke with Jesse Garon (aka "Reverend Elvis Presley") on Thursday, who is the lucky man that got to officiate Sophie and Joe's surprise nuptials.
Jesse told ET that he only knew that it would be a celebrity wedding he was officiating just minutes before things kicked off.
"I knew about five minutes before the wedding ceremony," Jesse told ET's Kevin Frazier on Thursday. "I knew somebody was getting married, I just didn't know who."
As for what Jesse thought when he first realized the groom was Joe? "That's the guy that sings 'Cake [by] the Ocean!'" Jesse recalled, referring to Joe's 2015 hit single with DNCE.
Earlier in the day ET's Lauren Zima spoke to Jesse, and he opened up about the planning that went into the surprise ceremony.
"They told us about a week in advance that [a couple] had rented out the place, but they wouldn't tell us who it was," he recalled, adding that, while he knew Joe, he didn't recognize Sophie, as he's not familiar with Game of Thrones.
"They rented the chapel from 8 to 12 p.m. but they really only used it from about 9-10:30, so it was pretty fast," he adds. "[They had] a bouquet, flowers and photographs."
Jesse says Sophie and Joe didn't really make any special requests out of the ordinary, other than having country stars Dan + Shay perform their hit song "Speechless."
"They sang really good, and then we did our ceremony and then at the end we did a little 'Viva Las Vegas' for them," he shares. "All the fellas jumped in and they enjoyed the heck out of it. We gave [Joe] some Elvis glasses, and a little bit of advice as he goes on his wedding night. We had a good ol' time!"
Joe's brothers, Nick and Kevin Jonas, were on hand for the nuptials, and Jesse says they both served as Best Man. "They did a very important job. In case [Joe] passed out, they were supposed to catch him," the Elvis impersonator jokes. "They did great."
"It was crazy," he continues. "These guys are all entertainers, obviously. They were loud when they needed to be loud, they dressed the part, for sure. And you could tell it was a tight-knit group of people, but it was about 40 deep."
One of those people was DJ Diplo, who was the first to share photos and videos of the ceremony via his Instagram Stories. "Diplo was the first one who came up to me, put his arm around me, wanted to take a picture. Cool guy," Jesse recalls. "It was a big [crowd] for a Vegas wedding. You think five or six is 'big' for a Vegas wedding... so, you get 40 people to come down and do something with you, it's quite impressive."
Jesse tells ET that once the ceremony wrapped, the party "kicked in" and Sophie and Joe (who wed with Ring Pops!) were adorably "lovey and in their own world," not really paying attention to anybody else as they waited to leave in a pink stretch cab limo.
Joe Jonas and Sophie Turner's Wedding: Elvis Impersonator Shares Inside Details (Exclusive)
"They were hugging and kissing up on each other," he remembers. "Very cute. From what I understand, they're going to have another ceremony, in a foreign location, but this is the main one. They wanted to do it and do it now, and I'm glad they did."
"[Joe] told me that he did some research, he looked at Elvis impersonators and had picked me," he continues. "I was flattered by that. I hope I get my invitation to that Paris wedding as well!"
A source told ET on Thursday that although Sophie and Joe are technically already married, they are still planning a bigger, more formal wedding, in Paris, France, later this year.
"Joe and Sophie are a couple that loves to have fun and live in the moment, and that's exactly what getting hitched in Vegas was," the source said. "The couple does plan to have a more formal wedding with their family and friends, but this ceremony was just fun."