Cheating is one thing, bringing a person into this world as a result of that cheating is something totally different. I am sure he's screwed around, and probably a lot, and maybe the worst was an STD or two but this is different.
If you had illegitimate children, would you refer to them as "parasites"?
The other side of this is we have no idea what's in this girl's mind. She didn't sign the NDA, all she knows is that her alleged biological father wants her to go away. I think that might mess with a young girl's mind.
However, if she and her mother are nothing but gold diggers, that's pretty much proof to me she's his daughter. Her father is a complete showoff with his money, why should she get some of that? He flaunts his richness right down to making sure we know the brand of scotch he drinks.