Spoken For by William Morrison

Half of Jupiter's great disk and most of the other moons were below the horizon when the man stepped out of the plane and changed her life. As far as Carol Marsh was concerned, he was ordinary enough in appearance. And she wasn't ordinarily attracted to ordinary men.
He was slightly over medium height, his features were not quite regular, and he had a deep tan over what had started out as a sunburn, so that she decided he had misjudged the strength of the sun on some planet with a thin atmosphere.
She frowned as she watched him look around. She was annoyed by the fact that it took him almost a minute to get his bearings and realize that she was first, a human being and second, a girl well worth a man's attention.
Even the troubled expression in his eyes was something she held against him. A man shouldn't look troubled. A man should be confident, self-assured in a manner that also assured the girl he spoke to. She remembered that back on Earth John Burr had been completely self-assured.
It was startling to realize that it was with this newcomer, whose appearance she had every reason to dislike, that she had fallen suddenly and completely in love, as suddenly and completely as if she had fallen off a cliff.