Hugh Hefner's wedding to runaway bride Crystal Harris, 26, is back ON

Despite everything she put him through, Hugh Hefner, 86, has become engaged AGAIN to 26-year-old Playboy bunny Crystal Harris

Harris ran off from the Playboy Mansion in June 2011 ... just five days before their big day, she then tried to pawn her engagement ring and fight the octogenarian for custody of their dog.

But there's no fool like an old fool, some might say, and according to TMZ, it's all on for keeps this time with a New Year's Eve wedding scheduled.

It's back on: Apparently Crystal Harris has realised she can't live without Hugh Hefner and their cancelled wedding is back on for New Year's Eve

They report: 'Harris and Hef are better than ever these days, since Harris moved back into the Playboy Mansion earlier this year.

'We're told the couple have worked out all their previous problems and decided recently they want to try and get married again.'

According to their sources: 'Harris feels the time she spent apart from Hefner really taught her how to be independent and stand on her own two feet, something she felt she needed.'

Traditional etiquette says that if the bride-to-be ditches the groom before they walk down the aisle she should give back the engagement ring.

But Harris not only kept the three carat diamond ring worth an estimated $90,000, but a Bentley too after leaving her former fiance Hugh Hefner at the alter.

Custody battle: Hugh Hefner is in a bitter custody battle with his runaway Playboy bride Crystal Harris over their pet dog Charlie

Shortly after Hefner and Harris ended their engagement in June 2011, the Playboy mogul said Harris let him keep Charlie, their shared Cavalier King Charles spaniel.

'We both love the puppy,' Hefner told People magazine. '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 'missed a bullet' by not tying the knot with Harris also added: 'The puppy's valuable, but not $100,000 worth.'

Caught in the middle: Charlie the Cavalier King Charles Spaniel is unwittingly caught in between his warring parents

Harris called off the nuptials at the 11th hour announcing her decision on her website.

'I have decided to end my engagement with Hef,' she wrote. 'I have the utmost respect for Hef and wish him the best going forward. I hope the media will give each of us the privacy we deserve during this time.'

She then went on to party in Vegas on the planned day of the wedding and gave a radio interview in which she said: 'I’m not tued on by Hef. He doesn’t really take off his clothes. I’ve never seen Hef naked.'

But Hefner refused to hit back, simply saying: 'The breakup is a heartbreaker, but better now than after the marriage.'

'After all is said and done, staying single is probably the best,' he posted on his Twitter account.

No tu on: Crystal said that Hef didn't do it for her after the first split

And he insisted they remained good friends.

The aging lothario originally took to Twitter the day after the couple broke up expressing his sadness about missing the dog.

'Crystal took Charlie with her when she left,' he wrote.

But he was thrilled to be reunited with the pooch soon afterwards.

'Crystal brought Charlie back because she thinks he's happier here & I appreciate it, because I really missed him,' Hefner posted.

Starring role: Charlie appeared with Crystal on the June 2011 cover she posed for for Hefner's famed magazine