Actually, somewhere in scripture it talks about the father's sin being perpatuated for four generations. BUT it says sexual sin is 10 generations. Must be He knows sexual sin is harmful to our families.
The marriage covenant in Scripture, since Genesis, has always been a metaphor for the relationship between Christ and His Bride, the Church.
In the OT, God always referred to idolatry and "adultery". Sexual sins, especially homosexual sins distort the picture of that relationship. That is why God hates it so much.