The New York queen and former boybander dated the TV presenter on and off in the early-to-mid-noughties, which Graham has described as a “whirlwind romance”.
However, things didn’t end well between the pair, and when they did finally call it a day, Graham admits he was “heartbroken”.
Writing in his 2014 memoir, The Life And Loves Of A He Devil, Graham recalls the night he met Kristian at New York’s Barracuda bar, describing him as “tall and broad-shouldered with an easy smile that took up half his face”.
But Graham’s friends weren’t quite as enamoured, and he admits that if Kristian “were to be judged solely on his behaviour, then I concede he was not great boyfriend material”.
He added: “What they couldn’t see was the special spark that fires within him: when he decides to shine his light on you, it makes you feel as special as he is.”
The romance lasted several months before the couple split, only for them to get back together again when Kristian moved into Graham’s London home.
“The experiment lasted for about six months and it was a disaster,” Graham recalled.
“I realise that even to a perfect stranger the outcome would have been glaringly obvious, but when you are in the middle of something and you are desperate for it to work, you’ll try anything.”
Eventually Kristian broke off the relationship.
“The madness was over,” Graham wrote. “But this time with no shouting or histrionics, just some slow, heavy tears shed over lunch in an empty restaurant.
“I walked home, finding some comfort in the fact that a man in his mid-forties could still feel such heartache.”
However, Graham has since seen Kristian performing as Tina Burner in New York saying “it seems like the perfect job for him… He gets paid to show off and drink”.