Simon Cowell and Sinitta were "devastated" after aborting their baby in the 1980s.
The 49-year-old singer has denied reports claiming she terminated the music mogul's child behind his back and that it happened as recently as 2009, insisting that it was a "heartbreaking" decision they went through together when they were both young.
In an interview with The Sun newspaper, she said: "Simon was very concerned and by my side. It was upsetting and it was something very difficult that we dealt with together. It's such a heartbreaking thing to go through. It was devastating for both of us."
The 'So Macho' hitmaker - who dated Simon on and off during the 1980s - admits the pair rarely discussed their loss and, instead, she bought a puppy to help her slowly get over the ordeal, but that didn't stop her longing to set up a family with the 'X Factor' boss.
She explained: "It's not something Simon and I talked about a lot. I got a puppy. It sounds weird, but that helped me get over it
"I have always admitted I wanted to marry him and have children with him -- not just because I love him, but because I thought I would be good for him."
The 53-year-old star is now expecting his first child with New York socialite Lauren Silverman, and Sinitta - who adopted Magdalena, eight, and Zac, seven, with her ex-husband Andy Willner - confessed she was "taken aback" when Simon rung her earlier this year to break the news to her.
She said: "I was stunned and taken aback, surprised. I was worried about him because he never wanted to have kids and now this was happening."
However, the brunette beauty - who admits she still has feelings for the Syco boss - felt betrayed by Lauren because they were like "sisters", but she insists the pair have since worked through their differences after meeting to discuss the situation.
Sinitta explained: "We are very, very good friends. When you've been close friends with someone and you're calling each other sisters and family and confided all of your secrets and feelings over the years to them...
"Lauren was that person to me. It was sad to discover that I wasn't that person to her. I've known her for four or five years. But it's OK, we have dealt with it."