In the laboratory, golden egg bugs copulate repeatedly, with copulations often lasting [greater than] 10 hours.
If it was previously in doubt, we now know that unmarried sexual partners can copulate without going to prison.
In the sexual race, worms have hermaphroditic sexual organs, and copulate and then lay cocoons filled with several fertilized eggs.
So if we have one man and one woman who copulate in the standard way, and not in any kind of other way that we find troubling, then they can raise children.
It's that plain and simple: find a mate, copulate , produce offspring, raise it, set it off into the world when the time comes, retire. That's what the Unromantics say.
Most species perform prelaying courtship feeding, which conflicts with mate guarding, and copulate frequently.
In the case of humans, the last male to copulate would be in a position to displace the semen left by previous males before inseminating the female with his own semen.
Also, males cannot force females to copulate as copulation is only possible when the female assumes a horizontal body posture.
However they are not expected to love them, just copulate with them.
Pairing copulations are preceded by females indicating their willingness to copulate by adopting the receptive position; females lie flat in the water to allow the male to mount.