They kissed and made up more than a year ago and now Gai Waterhouse and John Singleton are back together as racing partners.

Almost three years since a spectacular falling out after Singleton's racehorse More Joyous was beaten in controversial circumstances at Randwick, Waterhouse has a runner for the advertising mogul whom she famously called "old", "a drunk" and "an absolute sham".

Appropriately, it will be a horse called Kiss And Make Up who steps out in Singleton's racing colours with Waterhouse as the trainer when the two-year-old colt makes his racing debut at Canterbury on Wednesday.

Waterhouse and Singleton enjoyed a lifelong friendship which translated into major racing success until More Joyous suffered a shock loss in the 2013 All Aged Stakes.

The pride and joy of Singleton's racing team, More Joyous' defeat triggered a raceday outburst from the owner as he sacked Waterhouse as his trainer, accusing her of passing inside knowledge to her bookmaker son Tom.

It was a spat that was played out on national television before continuing in a highly publicised stewards' inquiry that included rugby league immortal Andrew Johns as a star witness.

Singleton was fined $15,000 for conduct prejudicial to the interests of racing while Waterhouse had two charges relating to the treatment of More Joyous overturned after appealing.

The feud ended during last year's Magic Millions yearling sales when Waterhouse paid $150,000 for a colt by More Than Ready out of the mare Fashions Afield which was presented as part of Singleton's Strawberry Hill Stud draft.

Raced by Singleton and his good friend Gerry Harvey and trained by Waterhouse, Fashions Afield was a Group One winner during a career that netted close to $2 million in stakes.

"She has bought one of my horses and we are looking at doing something pretty exciting together ... it will become apparent what it is soon," Singleton told News Corp soon after the auction hammer fell on the colt.

For Waterhouse, buying the colt signalled an end to hostilities with one of Australia's most recognisable business figures.

"It was a lovers tiff. I was very sad when it happened and I am very pleased he apologised and we have moved on," she said.

And if the bookmakers are right, there's every chance they will be reunited on a winning note with Kiss And Make Up one of the favourites after winning his past two barrier trial appearances.