The Erotic Mind-Control Story Archive

Big Tits Theory

Author’s note: There will be incest, but not until chapter 5. If you like, treat the first four chapters as a stand-alone, incest-free story, only opening the rest up if incest is your cup of tea.

Monday:

“Geez,” my brother said to me one morning, over a milkshake. “You sure are lucky…”

“Why’s that?”

My brother Marty and I had never been super close, but lately we’d been hanging out pretty much every morning. I think it’s the milkshakes—a couple of weeks ago, Marty got this machine that makes milkshakes. You wouldn’t think that making a good milkshake would be hard, but the first few he made were somehow revolting. It’s milk and flavor, right? How badly can you screw that up?

After a while though, something clicked, and he he really got the hang of it. I’m not kidding when I say that Marty’s Milkshakes are the single best milkshakes that I’ve ever tasted. They’re delicious, and each morning we both get up before school and he makes me a milkshake.

We’ve been using that time to hang out and shoot the shit. He’s a good guy, Marty—two years older than me, but he’s never been the dickhead older brother. We’d always just sort of lived our own lives, up until he got his magnificent milkshake machine.

Now? I guess we’re friends. I’ve been telling him more and more stuff about my life, and he’s been advising me…not in an over-the-top or patronising way, but just brotherly older advice. It’s been super nice: I really trust him.

“Well,” he said, strangely hesitant. “It’s just…”

“What is it, Marty?”

“You’re lucky that your tits aren’t bigger.”

I scoffed at that, but then saw that he wasn’t joking.

“…why?”

Now it was his turn to scoff.

“Are you telling me…you haven’t heard of the Big Tits Theory?”

The Big Tits Theory, according to my brother, was simple. In fact, more than simple—it was fundamental. He said it was a basic human fact: the bigger a girl’s tits, the more slutty she is.

Of course I thought he was kidding, but as he went on, he managed to convince me more and more…he’d really thought this one through.

Girls with A-cups, like me, were…well, prudes. Not sexually charged, rarely sexually active, and if we did get with a guy, it would be for a reason other than sex. Like a lot of the women in Game of Thrones—they’d sleep with men so that they could have children, or power, or for protection…but they never just did it because they were horny.

And though I’d obviously never discuss this with my brother, his theory was pretty solid so far. I’d never fooled around with anyone—I was a capital-V virgin. And, honestly, I’ve never really felt the urge to. I mean, it would be nice to find a guy who liked you, and maybe hold hands and kiss and all that, but sex? That was grown-up stuff.

I’d heard my friends talking about masturbation and boys going down on them, and it had all…well, it had all sounded pretty gross, to be honest.

B-cup was a “normal girl” he said, not even realizing the insult in his word-choice. They got urges, they masturbated, and maybe if they were in a long-term relationship, they’d fool around. C-cup was (again, his words) like “girl PLUS”. They were often horny, and it wasn’t super hard to get to second or third base.

D-cups, though…according to my brother, they were the motherlode. D-cups were the kind of girls who go out on the town, looking for one-night stands. If you make eye-contact the right way, they instinctively fall to their knees and their mouths pop open…you know the girls who hang around bands all the time, groupies? They’re almost exclusively made-up of D-cup girls.

“And so,” he’d said, finishing the last of his milkshake, “little sis—you are extremely lucky that you’re…well.”

He’d gestured to my chest, and I’d glared at him while slowly sipping the milkshake that he’d made me.

“I mean, if you were any other girl, I’d want you to be a C or higher. But my little sister…believe me, I wouldn’t have you any other way. You’re what, a B?”

“An A,” I’d replied quietly, almost embarrassed to admit it. Let’s face it, no girl likes being flat-chested.

“Oh,” he said sympathetically. “Well…don’t worry about it. You’re only 18…maybe you’re just a late bloomer?”

Yeah right, I’d thought, and gone upstairs to change for school. Looking in the mirror, I’d sighed. An A-cup. Doomed to a life of never wanting sex. The “A” could just as easily have stood for “asexual”.

I shook my head—what was I worrying about? Marty probably didn’t even know what he was talking about. “Big Tits Theory”…utter bunk.

But on the way to school, I started thinking about it, and I couldn’t think of a single example to prove him wrong…all of the sluts in my grade: Cindy, Stella, Ruth…they were also the girls with the biggest tits.

Sure, that could have been coincidence, or it could have been self-selecting (girls with big tits get more attention, and so they just have more opportunity to fool around)…but my brother’s theory held up across the whole spectrum. One of my friends I knew for a fact was a B-cup, and she’d only slept with her boyfriend after they’d been together for more than a year. Or Margaret—she was a large C, and she’d only been with Tom for a few weeks when they’d “done the deed”.

Staring out across the cafeteria at lunch, I wondered if my brother was right. Had he cracked the female code? In terms of evolution it certainly made sense…it would totally explain why guys always went for the girls with the biggest boobs—because they’re the easiest lays.

That night, I wanted to ask Marty a few more questions about it, but he was out on a date. I only saw her briefly, but his wink told me everything I needed to know…

He was going out with a D-cup.