Tease the plus-sized girl.

"Wow," you say, looking the voluptuous blonde up and down. Her huge tits are almost spilling out of her frilly pink bra, and her pink panties are too small to contain her gorgeous round ass. "Nice figure. You look like you can handle yourself. In an eating contest, anyway."

She blushes and folds her hands defensively over herself, thrown off her guard but not ready to give up. "I don't know what your game is, but you're going to let those ladies go right now or I won't be responsible for what happens next."

"You think you can threaten me? That's adorable."

"I don't know what kind of magic you have, lad, but I've fought wizards before. Must have cost you a lot of mana to rope up all these poor girls. Weren't planning on a fight, were you? Bet you're almost out. Now, you just let them go and there won't be any more trouble."

Instead of answering, you slow time. You unsnap the clasp of the blonde's bra and slip it off her arms, revealing a pair of enormous, soft, pillowy breasts capped with wide pink nipples that are just begging to be squeezed and stroked. You tie her arms behind her back with the bra, fixing it so she can't wriggle free, before you let time start up again. She lets out a small gasp as gravity takes hold of her heavy breasts, making them bounce attractively as they fall free of their confinement. Sammie's friends whistle and offer lewd comments as she squirms, a blush springing to her cheeks, unable to cover herself. "Hey! How did you..."

"Not quite out of mana yet," you say. "Now, I'm going to offer you a deal. Agree to do everything I tell you to do for the next 24 hours, and I'll let these girls go."

"I can still beat you, lad. As soon as I get out of these bonds..."

"I'm going to do it anyway. You could save these girls from sharing your total humiliation." You give Sammie's ass a firm slap, to punctuate your statement. "I thought you wanted to be a hero?"

Instead of answering she strains at the bra, trying to break it. The fabric, strong enough to bear the weight of her breasts, doesn't give way. Her breasts jiggle pleasantly as she flexes all her strength, trying to get her arms free. You shrug. "All right, then. Have it your way..."