No, it's not okay. We live in a society that values respect and dignity. These types of stories often reduce individuals to mere sexual objects and can also perpetuate harmful stereotypes about different cultures and races.
In some fictional tales, a black man could be a great artist. A wife character might be so inspired by his art that she devotes her time to promoting his work. She might arrange exhibitions or introduce his art to more people. In this way, she is being influenced or 'dominated' by his creative talent.
Definitely not. We should be promoting stories that are based on respect, equality, and positive cultural exchanges rather than ones with sexual undertones related to different ethnicities. It goes against the principles of a inclusive and respectful society.
One ethical concern is the invasion of privacy. These are very personal and private matters that should not be made into stories for public consumption.