The next morning

After a hearty breakfast Robb made his way to Littlefinger's brothel. It wasn't very busy, nobody visited a brothel in the early morning hours. Lord Baelish was, as expected, already informed about his visit and welcomed him with a sly smile. "Lord Stark, what an honour to visit my humble establishment."
Robb nodded. "Lord Baelish. I assume you received my gift?"
The Valeman bowed his head slightly. "I did, and I you have my thanks. Business was great yesterday."
"How many did she serve?"
"I did not count", Baelish admitted. "Since her services were free, I saw no point in restricting access. Towards the end, they just entered and left her room freely, at some point she had five men in there at once."
Robb felt slightly aroused at the thought. "Is she done now? I wish to see her."
"Of course. Follow me."
Littlefinger led him to a big, luxurious room on the first floor, filled with satin and silk and velvet. A white figure lay on the large bed, some shreds of her pretty dress still on her. Her auburn hair was in complete disarray, her back, her butt, her hair and her legs were covered in sticky white semen, her asshole was gaping and dripping with cum as well. She didn't move.
"Sansa", Robb said and grabbed her hands to turn her around. Her front side didn't look much better. Her cunt was torn open, there were bitemarks on her small breasts and her face was a battlefield of cum, tears and saliva. Her pretty blue eyes looked empty, she gazed right through Robb, even though she was clearly awake.
He felt the urge to fuck her as well, but not in this condition. "Have her bathe, and then give her new clothes. Expensive fabrics, but of course in a cut..." Robb looked at Littlefinger. "...appropriate for a whore."
The brothel owner just smiled and nodded, then called in two servants who carried Sansa away.

Robb killed some time by talking with Lord Baelish, then, Sansa was presented to him again. She walked on her own legs, somewhat shaky but without support. His sister was wearing a transparent silk dress that was fixed with two wolf pins on her shoulders. Her small nipples were clearly visible through the thin fabric, and it very sensually caressed her slender body without revealing it completely.
Her hair was clean of any cum again and shined in bright auburn as it always had. She wore it in a simple, but elegant hairdo. Her eyes were still somewhat empty as they had been before, but she seemed to recognize Robb.
"Very good", the Lord of Winterfell said. "I am told there is a secret path to the Keep?"
Baelish nodded. "Come with me."

Led by Littlefinger, Robb and Sansa (he had to grab her hand and drag her along) went back to the castle. He thanked Baelish again, then went to his room and sat Sansa down on his bed. She was his to use.