One possible plot could be that Sully and Michaela go on a long journey together away from their usual town. During this journey, they face many challenges and have to rely on each other. As they overcome these difficulties, their bond deepens and one evening, under a star - filled sky, they confess their deep love for each other and make love. It could be a very romantic and emotional encounter.
Perhaps Sully and Michaela are forced to hide in a small cabin during a storm. They are alone and start reminiscing about their past moments together. The closeness in the small space and the intensity of the storm outside heighten their emotions. They realize how much they mean to each other and that leads to them making love. It's a plot that combines the elements of danger and passion.