Rarity's bum was fantastic.
Twilight didn't mean to be objectifying here. Strictly speaking, her statement didn't qualify as objectification anyway. It's not like she didn't view Rarity as a person. A wonderful pony who was her dear friend. Twilight loved her for a thousand reasons. More numerous then the books on her shelves.
One of them just happened to be Rarity's exquisite bum.
And oh it was exquisite. It was big. Not too big for Twilight's tastes, or too small, but just the proper amount of thickness to satisfy Twilight's sexual tastes. It was also perfectly shaped. Round and beautiful. Twilight would just like to smack it. To see it ripple. To feel how it felt with her hooves or sensitive tail. Oh and Rarity's gorgeous tail. Well groomed of course and adding just that something as it swayed with Rarity's sensual hips.
Twilight shouldn't be thinking about Rarity's bum. She should be doing something more productive. Like study. Or read. Or reorganize the library. Or go for a walk. Or talk to her friends. Instead, she was eeking out some pleasure while Spike slept in, making up for the sleep he lost staying up late.
It would be fine if it was an occasional thing. Twilight had felt sexual attraction before. For both handsome stallions and gorgeous mares. However, this was different. This was like an addiction that just kept getting deeper and deeper. She was beginning to openly ogle her rear in public. It was getting obvious and Twilight was worried that her friends, the town ponies or even Rarity herself might find out. Andohcelestiawhataboutspike.
She should stop. Or at least focus on the other aspects of Rarity. Her lovely legs. Her gorgeous face, her fabulous mane...anything else but her marshmallow butt. Her amazing, addictive, extraordinary marshmallow butt, but still.
She needed to stop. Completely. Rarity wouldn't love her like she loved Rarity. Rarity was straight. But she just, couldn't help herself. How could she not love that generous, beautiful soul or her marvelous body. And she really should just stop because she was running out of adjectives. But obsession was a treadmill.
Twilight came silently to the image of Rarity's ass. And she moaned in guilt and shame. She shouldn't be thinking about her friend like this. If only pleasuring herself made it go away. Even just for the day, but the next time she saw Rarity's smiling face, or her big rump, Twilight would be head over hooves again.
Spike got up, stretching out his limbs before getting out of bed and heading down the stairs to the library, where he saw Twilight.
"Hey Twi." Spike said. Twilight jumped.
"Ah! Spike! I didn't see you there. You startled me." Twilight said, turning to face him.
"You've been super jumpy lately. You alright?" Spike asked.
"O-of course! I-I'm doing just fine Spike. Y-you don't have to worry about me." Twilight said. Spike narrowed his eyes at her for a moment.
"Ok. Just checking." Spike said, nodding and smiling.
"You doing ok? Sleep alright? After you got to be I mean." Twilight said.
"Yeah. I had the most wonderful dream about Rarity." Spike said.
"Y-you did huh?" Twilight said.
"Yep. She was looking particularly beautiful you know? She was wearing a dress that really complimented her butt. You ever notice she has a great butt?" Spike asked.
"N-no. C-Can't say that I have." Twilight said.
"Oh well. Anyway, Rarity was super happy in this dream. Really, really happy." Spike said.
"Th-that's nice. What about?" Twilight asked.
"And you were happy too. Really happy." Spike said.
"...I don't..." Twilight said, she wasn't understanding. But then she thought she might and her words caught in her throat.
"And because Rarity was happy. And you were happy...I was happy too." Spike said.
"I...I...see." Twilight said, tensing up. Feeling like she should bolt out of the room. Or teleport away.
"Go be happy Twi. That's all I want. I just have a silly crush. For you...it's love." Spike said, patting Twilight on the back and then he walked away.
"Hey! Where are you-?" Twilight asked.
"I'm going out to get some donuts. You can do whatever feels right." Spike said and he left.
Damn. Now she had no excuses. Twilight said, and her head fell to her desk.
She was going to have to confess.
Twilight was going to be hers. Rarity was confident in that. Twilight wasn't particularly hard to read, and Rarity relished the attention dear Twilight lavished on her. The glances and leers. The blushes when she was complimented. The compliments Twilight gave her, which were full of so many unspoken feelings. Soon Rarity would have Twilight. She would lick her marehood whenever Rarity asked. She'd take Rarity's horn wherever Rarity wanted to put it. Twilight would be serving her and she would enjoy it. After all there was that submissive streak Princess Celestia had so kindly nurtured.
If Twilight was disobedient, she would receive lashes against the rear in accordance with her crime. It would pain Rarity to harm that lovely rear, nearly as much as it would arouse and thrill her. She'd be trained to obey all that Rarity commanded. To be Rarity's little slut. She wouldn't need her library when Rarity was done with her. Or her pet dragon. Or any other friends. All she would need is Rarity. Anything else would just be an example of Rarity's generosity.
Rarity didn't know why Twilight, in particular, filled her with such a madness. Such a selfish kind of lust. Rarity hadn't even known herself to be into other mares til Twilight had arrived. Slowly but surely though, Rarity's mind continued to move along such lustful and obsessive pathways. It wasn't Rarity's fault that Twilight was such a seductive little minx. Rarity had been bewitched, so the only thing she could do, was capture her and make her hers. Anything else was unthinkable.
Every night Rarity shuddered herself to orgasm through vigorous masturbation to these thoughts. She wanted to tell herself that this was just a fantasy. That these thoughts were harmless. That she could control herself through self-pleasure. But Rarity knew that every night she was getting closer and closer to needing this. One day it would come true. One day she wouldn't be able to stop herself.
Rarity could only hope that Twilight was into this stuff as much as she was.