Backstreet Boy Howie D. Surprises Florida Couple at Their Wedding

— -- A Florida couple got the surprise of a lifetime when a Backstreet Boy crashed their wedding.

“Even now we’re still a little shocked,” the groom, Ryan Kastovich, 25, told ABC News today.

Kastovich and his bride, A’riel, 24, were in the middle of their wedding reception Saturday at the Front Street Civic Center in Melbourne when they were handed a letter from the Backstreet Boys' management team.

The letter, congratulating the couple on their marraige, was signed by four of the five Backstreet Boys’ members.

Minutes later, the fifth member of the group whose name was missing, Howie Dorough, walked into the reception.

"I’m freaking out and looking back and forth. I just thought, ‘No way,’” Kastovich said.

“I said to myself, ‘Is this real life? Is this happening to us right now?,’ and it was,” A’riel told ABC News.

Dorough found out about the couple’s love of everything Backstreet Boys after they posted a YouTube video in October inviting the band to their wedding.

“I was thinking people do prom proposals and get responses and they’re [Backstreet Boys] important to our relationship so I’ll try,” A’riel said. “It’ll be a great opportunity and memory for us.”

The couple’s YouTube video invitation was covered by, Rob Landers, a reporter for Florida Today, and spotted by a close friend of Dorough’s.

The friend, Tom Biddix, reached out to a local DJ who then contacted Landers to get the couple’s wedding information.

“I heard from the band’s management team on Tuesday, spoke with them on Wednesday, talked to Tom on Thursday and then had conference call with Howie and Tom on Friday,” Landers told ABC News of the short timeline to coordinate the surprise.

The only guests at the wedding who had any idea about the surprise were A’riel’s parents and one bridesmaid.

"They kept it secret for about five days which is amazing," said A'riel.

“I think they were going to faint at that time,” another wedding guest, Kastovich’s grandfather, John Kastovich, told ABC News. “It was incredible. Nobody had any idea.”

The Melbourne-based couple wanted the Backstreet Boys to sing at their wedding because they claim their lifelong mutual love for the band was the “spark” in their relationship.

“That was kind of the spark when we met,” A’riel said. “As Ryan being a straight male and saying he loved them, I was like, ‘Are you kidding me? I love them,” and that was it.”

Dorough serenaded the couple with A’riel’s favorite song, “All I Have to Give,” and even gave the groom a chance to join in.

“He asked me to finish off the song and it was only two words but I felt like the sixth Backstreet Boy that never existed,” Ryan said.

After posing for a few more pictures with wedding guests, Dorough left the wedding reception just as quickly as he had arrived, leaving near-speechless wedding guests and newlyweds in his wake.

“The best man and maid of honor speeches were after that and they were like, ‘How do we top that?,’” A’riel recalled.

“We’re so happy,” Ryan said. “To get married to your best friend and then to have Howie be there, I don’t even know what to say."