Severus held the tall, heavy door for Sabine by magic, because, honestly, it was ridiculously huge. He'd wondered since his school days why the main entrance to the castle had to be so obscenely large, and while he was far from physically weak, it was highly doubtful that he would be able to hold the behemoth of oak without a rather great effort. After the tall woman made her entrance, he allowed the door to shut, locking it securely in place.
"Then, I presume," he said with a slight bow, "That this is where we part. Good evening, Ms. Trefethen."
"Good night, Professor Snape," Sabine replied quietly, giving a polite nod of her head and brushing his forearm gently with her hand as she passed, branching out to an easterly corridor.
The gesture, she told herself, had been a reflex- after all, she was getting herself into the habit of acting the socially repressed wife.
Watching her leave, Severus felt his fingers twitch absently, and looked down in belated thoughtfulness at his arm. He curled his fingers into his palm again to quiet the tingling.
Stop that. He told himself severely, and descended into the dungeons.