You raced to the door to see who had just come back and the bright lights of Brad Jennings' Camaro told you everything you needed to know. Molly clambered out of the passenger seat and went around to lean in and give Brad a kiss through the driver side window. Then she came inside to find you standing in the door. 

"Snooping on sis, are we now? Tsk tsk tsk, Timmy. That's naughty."

"Where did you guys go? I don't like you hanging out with that guy Molly, he's got a bad reputation."

"Is that so? Hmm, in my mind he's got a pretty good reputation. A pretty big reputation if you know what I mean!" she winked. "And besides, what makes you think I'd listen to you, pipsqueak?"

You knew your protests against her dating Brad were in vain. She would do whatever she wanted. Besides, your motivations were a little selfish. You wanted Molly for yourself and felt like other guys didn't deserve her. 

Suddenly you realized two large points sticking out from Molly's sweatshirt. Her nipples were erect and practically poking you in the eyes.

"Are you not wearing a bra under there! Honestly, Molly..."

"In case you didn't notice, my tits are a little too big for a bra. At least any of mom's old bras, that is. Brad didn't seem to mind. Wanna know what he did?" 

Before you could answer, Molly lifted up her sweatshirt with a devilish look, making her boobs bounce free. You were too busy staring at them for the brief second they hung there to realize that she was lowering the sweater back down, over your head. All of a sudden, you were trapped in the warm dark space, your face pressed between your sister's colossal tits. You felt her nipples proudly sticking out and had to admit this turned you on incredibly. Molly held your head against her chest so you couldn't escape, though the truth was you didn't want to escape. It was so warm and soft, you couldn't imagine anything better. 

"Hahahaha, I think I like having you shoved down there, little brother. You make a good tit slave."

You tried saying something, but couldn't get any words out since your face was being smothered. After a few more seconds, Molly released you and smirked, seeing your hair was ruffled and your face was red. 

"Brad had about the same reaction. You boys sure do love my new body, I guess. Only thing different is after I shoved Brad between my tits, I sucked his dick dry. You don't deserve that Tim. God, you're such a fucking pervert, you know that? I'm bullying you and all you can think about is fucking your sister. I can see your boner so don't even try to hide it. Why don't you jack off as I go upstairs, hm? Watch your sexy big sis walk away and stand there, beating your cock. You better cum by the time I get to the top."

She turned and started up the staircase, her juicy ass swaying tantalizingly. She looked over her shoulder and saw you there, pumping up and down your cock. Molly rolled her eyes and continued climbing, her magnificent rear jiggling with each step. Just as she reached the top, you felt yourself orgasm, cumming in your pants.

It was then that you knew how much control she held over you. You were hers. She knew it. She loved it. And so did you.