In The Way of a Man with a Maid (published 1908), the first girl the main character rapes becomes his willing accomplice afterwards in luring and converting other girls - first, her maid Fanny.
>"But your mistress has ordered it, Fanny, and she tells me you are very sweet, and so I want it! And it will be like taking your maidenhead, only much nicer for you, as you won't have the pain that girls feel when they are first ravished and you'll be able to taste all the pleasure!"
>"No, no, Mr. Jack," she cried. "Don't … fuck me."
>Just then Alice came up with water, a sponge, and a towel. "What's the matter, Jack?" she asked.
>"Your maid says she doesn't want to be fucked, dear; perhaps you can convince her of her foolishness!"
>Alice was now sponging Fanny's cunt with sedulous care, and her attentions were making Fanny squirm and wriggle involuntarily in the most lovely fashion, much to her mistress's gratification. When Alice had finished, she turned to me and said, "She's quite ready, Jack! Go ahead!"
> … (two paragraphs omitted) …
>Alice, who was in my full sight and had been watching with the closest attention and the keenest enjoyment this violation of her maid, now bent forward and said softly, "She's all right, Jack! Go on dear!" Promptly I set to work to fuck Fanny, at first with long, slow, piston-like strokes of my prick, then more and more rapid thrusts and shoves, driving myself well up into her.
Of course, Fanny is converted to debauchery in quick order. Alice happily lends her to Jack when he asks.
>"Where to now?" I asked. "You are a pair of gadabouts!"
>Alice laughed. "My dentist's, worse luck!"
>"Poor fun!" I said. "For you or Fanny?"
>"Me, unfortunately. Fanny will have to sit in the waiting room."
>I glanced at her maid, and a sudden desire to have her again seized me.
>Fanny blushed rosy red over cheeks and brow. Alice laughed merrily as she regarded her blushing maid and caught her shy glances.
>"Certainly, Jack, as far as I am concerned!" she replied. "What do you say, Fanny? Will you stay and take care of Mr. Jack?"
>Fanny glanced shyly at us both. "Yes, Miss, if you don't mind!" And vivid blushes covered her face as she caught Alice's amused and half-quizzing look.
>"Then I'll be off!" Alice exclaimed. "Don't trouble to come down, Jack. Byebye, Fanny, for the present."
After Fanny is also converted to a willing accomplice, the three conspire to rape another of Alice's friends - a girl called Connie. Naturally, there is plenty of the two girls watching and assisting in the same vein.