The 40-year-old actress - who has daughters Sam, seven, and Lola, six, with ex-husband Charlie Sheen, as well as adopted baby daughter Eloise Joni - has responded to claims made by the 51-year-old music mogul that the pair were once set up on a "bizarre blind date" together.
However, Denise - who was eight months pregnant at the time - explained she had no idea she was being romantically pursued by the 'X Factor' judge.
Writing on her twitter page, she said: "I was at a group dinner 8mo pregnant not sure how thats considered a date, news to me! if I was being set up I didn't know it!
"s**t I wish I knew that it was a date!!! He's a hot piece of ass! (sic)"
Simon - who is now engaged to make-up artist Mezhgan Hussainy - admitted while he thought Denise was "a bit of a wacko", he "liked her a lot".
He said: "We had a bizarre kind of blind date several years ago. She's cute. She turned up eight months pregnant and had a dog in her handbag.
"She is gorgeous. I liked her a lot. I think she's cute, funny, a bit of a wacko, but I like that.
"We met up afterwards."