If love built a bridge between Britney Spears and Jason Alexander -- then the pop star's childhood friend-turned-brief-husband has apparently just burned it.

That's because Spears' ex has revealed in an interview with the British tabloid News of the World Sunday several explicit details about their sexual relationship and 55-hour marriage in Las Vegas in January.

"I didn't tell the world about this before because I still hoped we'd get back together," Alexander told the paper about Spears, who recently became engaged to one of her back-up dancers, Kevin Federline. "But I now realize she won't come back to me."

Alexander told the News that Spears proposed to him as she lay naked in his arms the second night the couple became intimate. And, he said, she kept saying how happy she was after they exchanged vows.

But Alexander said once they broke the news to Spears' family, it was the beginning of the end.

"We'd married just after 4 a.m. and by 7a.m. we knew we had to phone our families. It was horrendous," Alexander told the paper. "Britney phoned her mom and I heard Lynne screaming back at her. She went nuts."

Alexander said then Spears' brother called him and "talked about annulment."

"I didn't know what the word meant so I didn't say anything," Alexander told the News. Alexander said he phoned his father, and "at least he was fine" with the marriage.

"Britney told me to ignore her family and wanted us to run away on honeymoon straight away but we were so shattered we went to bed," Alexander told the paper.

But, Alexander was in for a rude awakening when Spears' brother arrived in Las Vegas with all her people and "they spread a load of papers on the desk and said if I cared about Britney I'd sign them." Alexander said he looked at Spears for help but she looked away, so he signed the annulment papers under duress.

Alexander said he's hurt Spears "didn't stand up and say she wanted to be married" to him. He also said that night they all went out to dinner and Spears was crying, but everyone else was laughing about what they'd done as though it was a big joke.