Hugh Hefner, Crystal Harris in a custody battle over puppy

Hugh Hefner insists he "missed a bullet" by not tying the knot with Crystal Harris.

STORY HIGHLIGHTS

• Hugh Hefner and Crystal Harris are fighting over their shared Cavalier King Charles spaniel


• "We both love the puppy," Hefner said


• "The puppy's valuable, but not $ 100,000 worth," he said

() -- Shortly after Hugh Hefner and Crystal Harris in June, the Playboy mogul said Harris , their shared Cavalier King Charles spaniel.

But now, Hefner, 85, says he and his former fiancée, 25, are still going back and forth about who gets permanent ownership of the pooch.

"We both love the puppy," Hefner told PEOPLE on Thursday at the Playboy Mansion in Los Angeles. "I told her if she wants to keep the ring and the Bentley, then maybe I can keep the puppy. I [hope] we will work it out."

Hefner, who still insists he "" by not tying the knot with Harris -- who was linked to Dr. Phil's son right after the split -- points out, "The puppy's valuable, but not $ 100,000 worth."

Life with Hugh Hefner

Although he is still in talks with Harris about their canine companion, Hefner has moved on in his personal life with Anna Sophia Berglund and Shera Bechard, the women he calls his "two very special ladies."