Putting this below the cut because it’s gross as hell.
Jeyne Poole was “given” to LIttlefinger in AGOT:
Queen Cersei looked at each of the councillors in turn. “I won’t have Sansa fretting needlessly. What shall we do with this little friend of hers, my lords?”
Lord Petyr leaned forward. “I’ll find a place for her.”
“Not in the city,” said the queen.
“Do you take me for a fool?”
The queen ignored that. “Ser Boros, escort this girl to Lord Petyr’s apartments and instruct his people to keep her there until he comes for her. Tell her that Littlefinger will be taking her to see her father, that ought to calm her down. I want her gone before Sansa returns to her chamber.”
When Jeyne arrives for her wedding to Ramsay in ADWD, we find out that:
“I was told that you’d know how to please a man. Was that a lie?”
“N-no, my lord. I was t-trained.”
…What was it the girl had said, before the godswood? They all said that I was pretty. She was not pretty now. He could see a spiderweb of faint thin lines across her back where someone had whipped her. “… she is beautiful, so … so beautiful.”
“I’m a good girl,” Jeyne whimpered. “They trained me.”
So Littlefinger took her to one of his brothels and had her tortured so that she would “willingly” train as a prostitute and take up Arya’s place later on. Which is one of many reasons that I can’t wait for Sansa to destroy him as the prophecy foretells.