You feel a slight pressure on your sides, the tall man having settled his hands on Kat’s breasts. He caresses and squeezes them gently, a look of happy disbelief on his face. “Damn, these are real aren’t they?” He says, looking up to address the crowd. Several of the onlookers cheer. Kat, however, isn’t impressed by his initiative.
“Let go of me!” She whimpers. “Let go of my... oooohhhhhhh!” She interrupts herself with a pleasured moan as you give her another size boost. The added weight throws her ridiculous figure off balance, and she topples forward, catching herself by wrapping her arms around the man’s neck.
“This bitch is just begging for it! Okay, okay, I’ll skip to the good stuff, huh?” The man laughs and gives her breasts a playful squeeze. They spill out of his grip in abundance. Kat’s breasts are ludicrously huge by now, and her sweater hangs in tatters off her sides. Kat herself looks a mess, her hair tousled and her mascara running down her face. “The... the bra,” she gasps. “It’s the bra... take it off, I beg you...”
The crowd hoots, and the tall man looks delighted to comply. “If you say so honey,” he says, squeezing her against him and reaching around to unhook her. You panic for a moment, but before you can try to think of a plan to prevent losing your power over her, you feel yourself tossed through the air. You land with a soft thump on the ground, only barely larger than a normal bra due to being stretched so far over your sister. In another disorienting overlay though, you find yourself staring up at the tall man with his hands around you at the same time. “Thank you, thank you so much...” you hear Kat’s voice three times over now. It hits you. Somehow, Kat’s magic has backfired again, and your consciousness has been absorbed into her breasts themselves!
You waste no time questioning this and get to work. “Oh god, my boobs are so huge... how am I going to fix—AAH!” Kat squeals girlishly as you force her ass into the air, still controlling her panties as well. This forces her to lower her breasts to the level of the tall man’s crotch, and you can feel the nudge of his cock in between them. You smile inwardly for your success, and press them inwards so they grip his cock snugly.
“No!! No more!” Kat says, tired enough from her dance that she can’t even raise her voice. “Please don’t make me do thiiiIIIIISSSS!”
You immediately cut her off again, setting her breasts bouncing rapidly up and down over the man’s cock. He throws his head back in pleasure, and rubs his hands over them in time with their motion. The excitement you feel seems to be affecting her as well, as her eyes roll back and her mouth hangs open in a narrow O shape. “STO... OH... OH... OH... OH... OH!” She tries to protest, her voice halting as her breasts bounce violently. “PLE... EE... EASE... STO... OH... OP... THIS... DAN!!” From the ground, you’re thoroughly enjoying watching your sister humiliated as she’s forced to titfuck a stranger. However, you make one last decision to rub it in, and you switch focus to her panties again. Tightening slightly, you start massaging her pussy and forcing thoughts of pleasure into it.
Kat’s tiredness suddenly disappears as she starts moaning out loud, unable to hide it any longer. “NOOOOoooooh!... D-DON’T MAKE ME CUM OVER THIS!... OH GOD IT FEELS.... soooooOOOHHHHHH.... NO! This isn’t m-MEEEEEEEEEEEEEE!!!” Kat screams. You suddenly feel yourself sopping wet, apparently she was closer to orgasm than you expected. As she goes limp, overwhelmed by conflicted pleasure, you switch your focus back to her breasts. They’ve been bouncing the whole time, but your tall friend seems like he could use some help too. You decide to try something else.
If being Kat’s bra can make her breasts expand, and being her panties can make her cum, could you make the man’s cock grow by being her tits? You focus your thoughts through them, only imagining the swelling and lengthening of his already sizable dick. It seems to be working, he looked happy before but he’s gripping her tits tighter now, humping them with total abandon. You double your efforts, letting only thoughts of a bigger, more sensitive cock fill your vision. Finally, over the top of Kat’s mountainous globes, you can see the man’s cockhead crowning from her cleavage. He clearly hasn’t noticed, eyes clenched right in ecstasy, but Kat definitely sees it.
“Oh god!! No, please...” she takes a few gasps of air, seeming to be on the verge of passing out. “My body... oh my body... please, no more!... don’t let him—!”
Kat is silenced as a jet of cum splatters across her face. She’s painted white from ear to ear, and it drips off her face in large dollops, raining over her enormous tits. You finally let her relax, and she collapses to the floor. Rope after rope of spunk arc across her, and the man likewise falls to his knees, a cock almost as long as himself jutting proudly into the air as it sprays. The crowd cheers wildly around you.