The longtime Bachelor host exclusively revealed to ET's Lauren Zima at the show's junket in Los Angeles on Thursday that he will be marrying Arie Luyendyk Jr. and Lauren Burnham at their wedding next month at Haiku Mill in Maui, Hawaii.
"You will see me at the wedding. And you know what? I can announce to you, breaking news," he shared. "I will be officiating Arie and Lauren's wedding."
Harrison -- who also officiated Bachelorette's Ashley & J.P. Rosenbaum's and Bachelor in Paradise's Tanner and Jade Tolbert's weddings -- said that the couple called him a couple of months ago to ask him to officiate their upcoming nuptials on Jan. 12.
"'They said, 'We'd really love it if you would fly out and officiate the wedding for us. We can't think of anyone better,'" he recalled. "I was really touched. I'm honored... it goes to show just how much we do care and love these people, and how tight we are off-camera."
"There's a few of us from producers and the Bachelor family that are going to fly out and be in Hawaii," he added.
'Bachelor' Couple Arie Luyendyk Jr. and Lauren Burnham Announce Wedding Plans
The news may come as a surprise to some fans after it seemed relations between Luyendyk and the Bachelor team weren't so great following his dramatic finale in March. The race car driver brutally blindsided his final pick, Becca Kufrin, when he ended their engagement just weeks later to pursue a relationship with Burnham. It all played out in an unedited breakup tape, and the next night, he proposed to Burnham.
"We are still close," Harrison confirmed. "I think it gets overblown because of how dramatic it is on TV, and I think sometimes you think what happens on TV spills over into our relationships, and most of the time, it does not. We are still close with the majority of the people on the show."
"It says a lot when people come back to be the Bachelor [or] Bachelorette, and it says a lot when they call you and say, 'Hey, will you stand before us and before God and officiate our wedding?'" he continued. "I don't take it lightly. It's an honor to stand before all the couples and do that, and it's something that's very sacred to me. I'm a faith-driven man, and so it's a powerful thing to be able to do that for people."
In addition to getting married next month, Luyendyk and Burnham are also expecting their first child together. Harrison joked that fans might hear a little nod to their expanding family when he gets up to officiate.
"Look, you know I'm not the most serious person all the time. There will be some anecdotal jokes in there, and we have a baby on the way, so maybe there's a [joke] about the fact that maybe we jumped the gun on the honeymoon suite," he said.
ET was with Burnham and Luyendyk as they shopped for her wedding dress and his tux in New York City in October. Watch below, and join ET's Bachelor Nation Facebook group here.