Scarlett Bride (The Scarletts: Book 6‪)‬

Marriage was the last thing on Dr. Oliver Scarlett's mind. He was looking forward to finishing his missionary stint in the Democratic Republic of Congo and then head for home. But, there was a damsel in distress, Ashaki Azanga, who was promised to be the fourth wife of the village chief and a life of hell.
According to his colleague, David Wheeler the only solution was to marry Ashaki and get her out of the country.
There were several problems with this solution: Oliver was no knight in shining armor and didn't want to be. His friend, David wanted Ashaki for himself as soon as his marriage was over, and most of all, Oliver was afraid that if he got to her know her better she would end up being his Scarlett bride for real.