[quote=@PharaohAtem]
Fair point however if we go with him still being trapped it still works for the same reason. Eventually he will be released even if it's not by Zeus and once he is free he can go back in time to father a mortal child.
[/quote]

Why?

I have certain reservation about a character, even a god level one having the type of time manipulation you're talking about. Mostly because it begs the question "Why doesn't he return to the Titanomachy and use the fact that there are two of him (or more Reverse-Flash style) to end up winning the war in the first place."

But putting that aside by and large when the titans ruled the earth humans were nothing more than cattle. If he's newly released that's still the mindset he's going to hold. While I can totally see him sleeping with a human as the fancy strikes him, going back in time to do it seems like a massive expenditure of power to do something that he could just as easily do in the present day. It'd be like going back in time to make yourself a sandwich instead of just making yourself a sandwich.