Aging CNN talk-show legend Larry King is in the doghouse after explosive allegations surfaced that he bedded the beautiful younger sister of his wife of 13 years.

King, 76, filed for divorce from his seventh wife, Shawn Southwick, 50, in a Los Angeles court yesterday in the wake of the eye-popping allegations. It's the suspenders-wearing chatmeister's eighth trip to splitsville, as he divorced one of his wives twice.

Southwick filed for a split the same day. Both cited "irreconcilable differences."
Sources said the pair fought bitterly for years over her belief that King was sleeping with Shawn's younger sister, Shannon Engemann, 46.

King spent $1 million on Engemann and lavished her with gifts, including a $160,000 car, sparking Southwick's ire, according to Radar Online.

But Engemann, a model and voiceover actress, denied any romance. "It's just ludicrous, really," she told The Post. "Larry's been a good friend and he's been like a father to me."

She said "there's a lot of other things wrong" in her sister's marriage, "and all of a sudden, it's my fault . . . Now this is just crazy."

Radar and the National Enquirer both reported that Southwick has carried on a torrid yearlong affair with her kids' baseball coach. She's denied it.

The constant warring between Larry and Southwick got so intense, it erupted into a slap-fest outside a Beverly Hills restaurant on Feb. 7, Radar reported.

But as accusations over philandering grew more heated, King signed over real estate -- including a Beverly Hills mansion -- to Southwick to show his commitment to the marriage, TMZ.com reported.

"We're not commenting on that," Howard Rubenstein, a spokesman for King, said of the cheating allegations.
King has not only married a slew of beauties, he's dated a few, too, including actresses Angie Dickinson and Deanna Lund and ex-beauty queen Rama Fox.

King and Southwick got hitched in a hospital room in 1997 before he went under the knife to clear a clogged blood vessel.

The talk titan and Brooklyn native wants joint custody of their sons, 11 and 9.
"His major concern is the welfare of his children," said Rubenstein.