I feel that it was more that the goddess had the power to tell him no

If you're immortal, wouldn't you want your side piece to be mortal so they wouldn't hang around forever?

Imagine getting a clingy ex that was also immortal. "Remember that time we hooked up 8,000 years ago? We should get back together."

Because he bangs them and then they die after a few decades. Problem solved.

Those goddesses stick around.

The Why: He was terrified of the prophecy/curse on his lineage, that the leader of the greek "gods" would always birth a legitimate (son) that would rise up and kill the father.

He did it to his dad, his dad did it, and it is basically why he's such a whore as well as why Athena birthed from Zeus' forehead, he had eaten her right from the womb as an attempt to erase her.

Ain't no golden shower like stormy with a chance of Zeus spunk.

...

Acrisius was disappointed that he had no sons to give his throne, and asked an oracle for help. The answer he got was that his grandson would kill him. At that point, Danae was childless, and to keep the prophecy from coming true, Acrisius locked her in a tower. However, Zeus had seen Danae and had grown fond of her; so, during the night, he appeared to her in the form of golden rain and impregnated her. She gave birth to a baby, which she named Perseus.

...

Source: https://www.greekmythology.com/Myths/Mortals/Danae/danae.html

Uh... hail to the king, baby...?

Well, iirc, weren't most of them like his sisters, daughters and so on?

Because hole.

From what I remember the last time you posted this, even the hole is optional.

Typical man...