If you are not going to marry her, then keep your hands off another man’s future wife!
This is the logic of Islam.
Discussion
Is smash and release ok though? Or does she have to be a virgin to get married?
Ok. Is that logic exclusively focused on one man’s obligation to another man? Another words is the prohibition of extramarital sex based upon any other moral grounds?
It is all moral grounds. Best for all current and future parties. Including future spouses and children. Women are especially vulnerable here as they cannot protect themselves in a sick society
In terms of a man’s obligation to his fellow man, could polygamy be detrimental to one’s fellow man depriving some men of having a wife?