It's a good question, there's no need to make it a leading question.
I'd probably answer with the following.
"Why not tell her the truth? Tell her, 'I believe that my sexual desires are more important than the need for you to have a father.'
Or you can tell her that I'm an evil man keeping you from being truly happy."
Whichever makes you sleep better at night.
You are an evil man trying to keep the children of gay couples from being truly happy.
Why, exactly, do children need a mother and a father? Is there any evidence, backed up by science and logic, that proves that gay people are worse parents?