[Pharaoh]

Well, let's look at what unnatural really means.

unnatural
adjectiveÂ*
Definitions:
Â*
1.Â*contrary to expected behavior:Â*contrary to habit, custom, or practice
an unnatural tense silence between them
2.Â*not conforming to conventions:Â*behaving in ways that contradict conventional assumptions about what constitutes normal or acceptable human behavior
3.Â*artificial:Â*affected, artificial, contrived, or strained
an unnatural festive atmosphere
4.Â*contrary to laws of nature:Â*contrary to the physical laws of nature

You could say a man on the moon is unnatural (1) or processed meats (3) and maybe travelling in cars (4), but you can't just say everything is unnatural. Being unnatural isn't necessarily bad in itself, travelling in a car or watching TV won't harm you but eating unnatural foods and breathing unnatural air isn't so good.
Having two gay men as parents is unnatural and unnecessary and isn't likely to be good for a child.