After receiving a text message that read: I H8 U, loser! Federline, 28, became visibly upset, removed his microphone and left for a half hour before returning to finish an interview.

    "He had no idea it was coming," a Federline pal told The Post. "In fact, he had been looking into a possible divorce. She beat him to the punch."

    But sources familiar with the couple's marital problems say the the writing was on the wall.

    "He knew what was happening," said a music-industry insider who has worked with K-Fed. "They were separated for months."

    In fact, Federline has been lamenting that she was holding him back.

    "I will never make it big as long as I am with Brit -- I will always be Britney Spears' husband," the insider quoted K-Fed as saying.

    The source said Spears, 24, attempted to prolong the doomed union through the launch of Federline's new album out of pity.

    "It's about time," someone close to Spears told the upcoming issue of People. "During the whole pregnancy, they had problems. She tried to support him as much as she could, but at the end of the day, she realized it wasn't best for her and her children [to stay]."

    Only three weeks after Spears gave birth to Jayden, Federline and his entourage flew to Las Vegas and booked tables at the club Tao for at least two straight nights, and were seen "surrounded by women, drinking a lot and dancing on the banquette," a source told Page Six at the time. "But every time one of the girls tried to take a picture, he freaked out and wouldn't let them."

    One day after Spears filed for divorce from husband Federline, the rapper responded on Wednesday with court papers seeking spousal support and custody of their two children.

    Fed-ex submitted his response in Los Angeles Superior Court, the same courthouse where Spears suddenly filed for divorce on Tuesday after two years of marriage, citing irreconcilable differences.

    The court papers show that Spears and Federline were prepared to fight over custody of the children in what could be a bitter divorce proceeding.

    According to the Sun, Britney and Kevin had a bitter row before Kevin's performance for the West Hollywood Halloween Carnival last Tuesday, which ended with Britney screaming at him "You're useless -- you're a nobody!"

    After she stormed out, Kevin was spotted kneeling and crying in a corner.

    But he doesn't appear to be crying now, instead Federline is advertising his new status, letting the ladies know he may still be married, but he's available.

    At Chicago's House Of Blues on Wednesday night, he told the crowd: "Hey, I see a lot of fine ladies in here. You know I'm a free man, right, ladies? You wanna dance with a pimp?"

    (Agencies)