Solo career came sooner than expected for B2K singer

Former B2K lead singer Omarion hadn’t expected to go solo just yet, but when the teen-sensation quartet splintered while on tour last year, he knew it was time to go it alone.

“Everybody kind of wanted to do their own thing, and everybody kind of ventured off,” says Omarion, 20, who addresses the breakup in the song “Growing Pains” off his first solo album, “O.”

The CD, which debuted at the top of this week’s Billboard album chart, is accompanied by an MTV-published autobiography of the same name.

“There was some bitterness in the beginning, but everyone fixed their relationships, and that’s what’s important to me,” says Omarion, whose full name is Omari Grandberry. “Our friendship was what kept us bonded when we were a group.”

The Los Angeles native thought he would be like older brother Marques Houston, who for years stayed with his partners in the teen band Immature, who grew to adulthood as IMx.

“They bred us to be the type of group they were, and it’s a shame that we didn’t end up like that,” Omarion says.

At least he knows what to say to 18-year-old brother/singer O’Ryan, who released his self-titled album in October.

“He’s just getting started, and the conversations that we have are the same ones that IMx would have with us,” Omarion says.

Omarion, most recently seen as Cosby crew rival Reggie in “Fat Albert,” also is juggling a budding acting career.

He also starred in the dance-focused drama “You Got Served” with older brother Houston, and they have a two-picture deal with Paramount/Sony Films.

A horror film, “The House,” begins shooting in April. Details of the other film, “Soldiers,” are sketchy, but Omarion says it’s in the same vein as “Served.”