ALYSSA MILANO is dating her hunky “Charmed” co-star Brian Krause — whose five-year marriage ended after he arranged a secret date with Alyssa behind his wife’s back!

“Brian and Alyssa looked so happy together, holding hands, kissing and gazing into each other’s eyes,” an eyewitness told The ENQUIRER.

“They ordered an early dinner at the Malibu Seafood restaurant. Then they walked hand in hand along the beach.

“They stopped and kissed and watched the sun sink into the horizon.

“At one point, they just sat in the sand and held each other. It was very romantic.”

Brian — who plays guardian angel Leo Wyatt on “Charmed” — was still married when he planned an outing with Alyssa, without telling his wife.

The 32-year-old actor secretly arranged a day of riding horses with Alyssa, 28, last December while his wife Beth was in North Carolina visiting relatives.

But Beth got wind of his plans and flew home early.

“When Beth got back to California, Brian screamed at her and called her names,” said a source close to Beth.

Disney animators used a picture of Alyssa to create the character of Ariel for the animated film “The Little Mermaid.”

“Brian even accused HER of having an affair. Finally, he stormed out.

“Beth soon suspected Brian was cheating, but she’d never linked him with Alyssa. His secret date with Alyssa was the last straw.”

Beth filed for divorce citing “irreconcilable differences.” According to divorce papers, the couple separated on Jan. 5, 2001. They married in July 1995 and have a son Jamen, 5.

Beth, a former NASCAR Winston Cup model, told The ENQUIRER: “Filing for divorce was nothing that I wanted to do, but I think it’s the best thing for us.”

Alyssa’s marriage to rocker Cinjun Tate lasted only 11 months. They split in December 1999.

A friend of Alyssa’s revealed:

“Alyssa started hitting on Brian on the ‘Charmed’ set and he went along with it. No doubt about it — they’re having a hot and heavy affair.”