To those who aren't familiar with what is going on, read Big Macintosh: The Stallion of Many Mares. The best way to understand what's going on is to read the whole thing. However, the best chapters that will help you understand quickly are chapters 1, 2, 6, 14, 15, and 16.
After being picked up by Cheerilee's sister, Cherry Blossom, Cheerilee and Marble Pie went over to the place that Cherry Blossom's friend is currently living; it's a huge housing complex with 10 floors on it. They headed to the 7th floor, where Cherry Blossom's friend is staying. Cherry Blossom's friend is a unicorn named Sun Star; he has blue eyes, yellow skin, a red and yellow mane style and tail, tall, very muscular, and sun with star in the middle of it. He was coming back from the pool and had on a black swim brief and white shirt on.
"It's good to see you again Cherry Blossom" said Sun Star as he entered the house
"It's good to see you too Sun Star" said Cherry Blossom as she gave him a hug
"I take it these are your friends. (to Cheerilee and Marble Pie) Sorry that I'm not decent; I didn't expect Cherry Blossom to bring in such lovely mares with her." said Sun Star
"This is my twin sister Cheerilee; she's a teacher in Ponyville. This is her friend Marble Pie. I hope you don't mind, but they need a place to stay for a few days." said Cherry Blossom
"Of course they can stay. Now if you'll excuse me, I need to shower; make yourselves at home." said Sun Star
"Cherry Blossom, how do you know this stallion?" Cheerilee asked her sister
"He works at spa here in Manehattan; he's in charge of the tanning area of the place. I go there a couple times to relax my body and to get a nice tan. He also doubles as somepony that gives other ponies sexual intercours improvement; he likes to call it Pleasure School. He helps mares improve their sex drives by giving them advice, new techniques, and sometimes hands on approaches " said Cherry Blossom
"Is that how you know him?" said Marble Pie
"Yes and he used to help all the female wrestlers recover from injuries too. I first met him when I broke my leg and he helped me through it. He also taught me some sexul positions that helped me on dates. If you want, I could set you two up." said Cherry Blossom
"No thanks! Me and Marble Pie already have a stallion that we both love." said Cheerilee
"What do you mean "we both love"? Are you two in a harem of sorts?" said Cherry Blossom
"What makes you say that?" said Marble Pie with a nervous look on her face
"Your choice of words and what I read about in the Manehattan paper rumor section; there's a rumor that Fancy Pants has a secret harem of 28 mares." said Cherry Blossom
"I guess there's no point in denying it. We are in a harem, but not with Fancy Pants, but with somepony else. His name is Big Macintosh, or Big Mac, and we're in his harem. He's here because he's in a pornography contest to help pay off somepony in our harem's debt for some costumes that she gave us. We came here because me and Marble Pie had something special planned for him" Cheerilee explained to her sister
"Don't tell anypony about this; same goes for you friend if he just heard us." said Marble Pie
"I won't say anything and I'm sure if he heard us, Sun Star won't say anything either. But girls, you should consider taking some lessons from Sun Star. He's helped not helped mares improve their sex drives, but taught them techniques that really helped them keep stallions interested in them for a long time. You should consider it, especially since you two are sharing one stallion that will eventually have more mares coming to him." said Cherry Blossom
Later that night, Cheerilee and Marble Pie stayed in the guest room that Sun Star showed them to after they had dinner with them. Cherry Blossom also gave them some of her spare clothes for them to wear in bed and whenever they go out to look of Big Mac again. As they were getting ready for bed, Cheerilee used a glass to overhear Cherry Blossom and Sun Star; she could hear the two having sex.
"Why are you listening to what they are doing?" Marble Pie asked Cheerilee
"I'm just curious. And I've been thinking about what my sister said." said Cheerilee as she got up and stopped listening
"What do you mean?" said Marble Pie
"Marble Pie, we entered into a harem with Big Mac and chances are it will increase by means that we can't control. If we can't stop it from increasing, we have to find ways to keep Big Mac interested in us. I'm going to take that class he's offering and learn new tricks to impress Big Mac.(in her mind) Also, I want to learn enough to make Big Mac consider me his number one mare in his harem; I may be able to get him to marry me and have his baby/babies if I do well."
"If you're doing it, then so will I. It's like you said, we're in a harem and we'll have to step things up a bit. (in her mind) I have to step things up a bit if I'm going to make sure Big Mac is around for me to choose him as my husband rather than the choosing stone; I want to be his wife and have his baby/babies." said Marble Pie