Britney Spears' Ex, Jason Alexander, Reflects on 55-Hour Marriage: 'I Was in Love'

Feb. 4, 2012— -- In the U.S., the average divorce comes after eight years of marriage. That's 24 times longer than Renee Zellweger and Kenny Chesney lasted; 40 times longer than Kim Kardashian and Kris Humphries; and 324 times longer than Dennis Rodman and Carmen Electra.

But Rodman and Electra are a regular Burns and Allen (that's George Burns and Gracie Allen, kids, who stayed married 38 years until her death) compared to Britney and Jason. Britney Spears and her childhood friend, Jason Alexander, were married for 55 hours, one-1,274th as long as the average American marriage ending in divorce.

For Alexander, it all began -- and ended -- on New Year's in 2004. Spears invited him to Las Vegas and flew him there in a private jet.

In an interview with ABC News correspondent John Berman, Alexander said he went thinking he would simply "have a good time."

"It wasn't really a booty call," he said. "It was just, you know, a friend asking a friend to come on a trip."

Alexander did say he and Spears, who grew up together in Kentwood, La., had once been friends "with benefits" -- even when she was dating Justin Timberlake.

"There was an instance when [Britney and I] were hanging out," Alexander said. "He had called, and I was ... kicking it with her, kind of like the guy 'behind the scenes' no one knew about."

Then came Las Vegas, and he was behind the scenes no longer.

"She just came out and asked me," Alexander said. "She was like, 'Well, let's get married.' And I was like, 'Sure. You know, let's do this.'"

Alexander said they were drinking and "had party favors." What kind of party favors? "Oh, a to z," Alexander said, smiling.

Asked if he meant drugs, Alexander replied, "Alcohol is a drug. Coffee is a drug. Cigarette is a drug. Yeah, we were doing drugs."

Whatever their state of intoxication, Alexander said he was also riding a wave of emotion.

"I went with my feelings," he said. "I was in love with her. ... I feel like she felt the same way."

They went to the little white wedding chapel, exchanged vows and posed for the infamous photo with Spears sporting a white baseball cap and a bare midriff. It all seemed so promising.

Alexander confirmed there was a honeymoon of sorts.

"I mean, we were in Vegas, you know. I mean ... well, we had a suite. Hmmm," he said.

When he and Spears shared the happy news with her mother and managers, Alexander said, "everyone went crazy because there was no prenup."

"They didn't want to hear anything ... and [Spears] came back, and it ended," Alexander said. "That was pretty wild."

The marriage was annulled. The annulment said Spears "lacked understanding of her actions, to the extent that she was incapable of agreeing to the marriage."

"Bullsh**," Alexander said.

Alexander said he signed the annulment papers because he was being a nice guy, and he hoped they might get back together.

It hurt, he said.

"That was probably the hardest part about it," he said. "I had obviously got my feelings involved."

"I didn't get paid. I didn't make any money, uh, directly from that," he said.

He flew coach back to Louisiana.

Alexander is pursuing a career as a fighter in mixed martial arts.

What did he learn?

"Don't be a nice guy," he said with a laugh. "Nice guys finish last. Look out for yourself. If you are going to really get involved into a relationship with a celebrity and you are just an average Joe, make sure you are thinking business!"

In an interview with E! a few months after the annulled marriage, Spears described it thus: "It was me being silly, being rebellious."

Spears has since been married and divorced to Kevin Federline. She is engaged to her former agent.

Watch the full story and interview with Alexander on the full episode of "20/20: HOLLYWED."