The title might have started "If you were a M*"

I read this story about 2015 but it seemed to be written some decades earlier. A small number of human men are living on a planet inhabited by an intelligent alien race.

After the humans arrive many of the alien children born look very like the individual humans on the planet. If an alien mother comes to visit a human with a child resembling him, the mother is given a gift by him.

Authorities from Earth are angry because they assume the humans have been fathering children with the female aliens. They believe that the aliens are being exploited.

One alien little girl even has a moustache like the human she resembles. At one point in the story, there is an intelligent tree.

Spoiler

The eathmen had not been sleeping with the aliens. The aliens had the ability to use their minds to alter their unborn offspring.

It became very fashionable amongst the aliens to make a child resemble a human they liked. The humans took this as a compliment on their appearance so gave a gift to the family of each such child.

The authorities on Earth realised they had misunderstood the situation when they sent a woman to the planet to investigate. An alien baby was born looking like the woman.

At the end, one of the human looking aliens has grown up and leaves the planet on a human spaceship. He pretends he is the human his appearance was copied from.