Route Threeway To Climax

She is married to Damien and she is sleeping with both of his sons, and Damien does not know it. The party is on the move, running from something and heading for a safe house, which keeps her within a few feet of her stepsons the whole way. She says she never meant to betray her husband. It happens on horseback, then on a boat in a storm, then on a night train with Damien sitting in the same carriage. One of the two she calls fire and the other a dark she gets pulled down into. At some point she stops being able to say she does not want it. The safe house is still a few kilometres off and they have not reached it yet.