Liz Hurley says she is deeply hurt by claims by Stephen Bing that their relationship is not "exclusive".
The actress model hit back after Bing broke his silence to cast doubt over whether he is the father of her child, as the mum-to-be claims.
In a statement, the film producer says he and Hurley were not in a "exclusive relationship when she became pregnant".
The statement said: "It is her choice to be a single mother. The insinuation that I would not care about the wellbeing of another human being has been very hurtful to both myself and my family.
"If indeed I am the father, I will be an extremely involved and responsible parent."
Hurley, 36, says that as far as she is concerned their relationship was exclusive and she was loyal to her lover.
She added: "I'm deeply distraught by Stephen Bing publicly declaring that he hadn't been in an 'exclusive relationship' with me.
"This was the first I had heard of this and the implications are very painful, especially as I am shortly to give birth to his child.
"I loved Stephen enormously during the 18 months we were together. Contrary to erroneous reports, we were still very much happy together when I discovered I was pregnant.
Bing, 35, has pledged to be a "responsible parent" if he is the father of the baby, which is due in April.