The X Factor creator was cornered by Ryan Seacrest on his radio show when he mentioned Simon's "girlfriend".
"Which one?" Simon cracked, before admitting "we've been on some dates".
He added: "She's adorable, isn't she?"
Earlier this month, Carmen pulled the old "just friends" line when asked about Simon by the US Today show.
"We're friends and he's an awesome person. I adore Simon," the former Baywatch actress said.
Carmen and Simon became close when she appeared as a guest judge on Britain's Got Talent in February.
The pair have since been spotted kissing and canoodling on numerous dates.
Simon has a track record of attracting beautiful celebrities and models view his full catalogue of women (that we know of) here.