Hugh Hefner on Holly: "It's Over!"

Playboy mogul says he and Holly Madison have called it quits; other women waiting to replace her

It's really over.

Hugh Hefner confirms he and Holly Madison are no longer.

"If she says it's over, it's over," Hefner tells me. "But like I've said before, she is the love of my life, and I expected to spend the rest of my life with her."

The Playboy mogul says the relationship started to crumble about six months ago when they learned he was unable to father a child with Holly.

"With my sperm count, it's not possible," Hefner explained. "I was willing but it was not possible…She'd like to be married and have children, but it's not in the cards here for me."

Where does that leave the other two Girls Next Door, Kendra Wilkinson and Bridget Marquardt?

Hefner says they're still romantically involved, but admitted, "the relationship with Kendra will be ending when she moves out, probably by the end of this year."

Hef ain't wasting anytime getting back in the saddle though.

In the last week, he's been spotted with 19-year-old twins Kristina and Karissa Shannon (pictured above). "They very much want to be girlfriends and now under the present circumstance, they probably will become my girlfriends," Hefner says.

And they're not all he has to look forward to.

A college senior from Georgia whom Hefner identifies as Amy Leigh Andrews is also waiting in the wings. "She was testing here this past weekend," Hef says of the centerfold wannabe, "and she said she'd like to be a girlfriend, too."

The 82-year-old Hefner laughed, "I'm dancing as fast as I can."