The pop princess will be shocked to learn that Olivier Martinez formally introduced the Israeli beauty to his family in Paris last December.
Kylie was touring Australia at the time — the couple didn't end their four-year romance until February.
And Olivier's relatives say that when he presented Sarai to them he was smitten with the writer and actress, who stars in cult US TV crime series CSI.
One said: "French custom is such that when a man introduces a female friend to the family they're more than just good friends.
"Sarai is beautiful and intelligent — all the qualities Olivier loves in a woman. We thought she was fantastic."
But at the time, when Olivier, 41, and Sarai, 24, were pictured strolling through the French capital, he insisted they were just good friends.
Then in January, we revealed stunning Sarai had visited Olivier again, this time at his suite at LA's Chateau Marmont hotel — while Kylie was 5,000 miles away touring in the UK. Kylie and Olivier held crisis talks and split a week later.
The family source added: "They are extremely close and enjoying spending time together. What's wrong with that?
"He mentions Sarai a lot when he calls from LA. We can tell when Ollie has the hots for someone nowadays."
Olivier's dad Robert also confirmed his son is dating Sarai, saying: "Yes, he's still seeing her — he's entitled to spend time with whoever he likes."
On a trip to Paris last month Kylie spent time with Olivier's dog Sheba, but never met her ex. The relative said: "They rarely see each other in person."
But brave Kylie, 38 — who has beaten breast cancer — has bounced back from the split. She's planning a new album and next month will have her smile splashed across billboards for the "H&M loves Kylie" range.
And last week she washed that man right out of her hair with a rinse and dye in a Paris salon.
A passer-by said: "I couldn't believe it. I looked in the window and saw Kylie having her hair done."