It needs to be discussed

It was the very next day and you were ramming Carrie's ass with brutality, to her very sonorous delight. She just got back from her weekend and had fallen to the floor on all fours as soon as she had passed the door, begging you to fuck her hole to satiate her starvation, to which you happily obliged.

"So, what's next?" she asked between two thrusts. "Do you want me to make Cass as much a whore as I am?"

You groaned before answering "Maybe not as much. I'd like her to be as hungry for sex as you are, but now that I know she never had sex with a man, I like the idea of being her only man."

She moan and laughed, waving her hips on your shaft. "I guess she can sleep with any girl she wants, though."

"Hrrn... I guess... Yeah! But I'd like you to be her first. I mean, even before me." you say while your dick goes deeper into her ass. You're her mentor, after all."

"You bet I am! Hmm... Ok, so next time we are the one inviting her to our place." Her screams go higher and higher.

"Sure! I can't wait!"

"Neither can I, I'm comiiiiiiiing!"

Cassidy's visit didn't happen immediately, as she still had to go to college. However, the two sisters where far more in touch than ever before, constantly calling each other, chatting and talking about topics they never adressed before. Carrie let out victorious exclamations every time she had her little sister confess one of her naughty sides, which turned out to happen a lot. She never missed an opportunity to invite her to come along, talk about her life with you -mostly your sex life, actually- or mention that the local college provided the same education as the one she attended, and possibly a better one. Slowly but surely, she was strenghtening their bond. It lasted until finally, the younger sister had an oppurtinty to come to your place.