Family Ties/Try and break free.
You refused to take this sitting down, just letting Heather win like this as she teased you just a few feet away. You struggled and pushed against your bonds; shaking the chair as you did.
Heather barely looked bothered at your struggles and just stared at you, amusement shining in her eyes. "Aw is my adorable baby brother trying to break free so he could pay me back? How adorable." She pinched your cheek a bit and back to eating, sitting back to enjoy the show.
You growled a bit and doubled your efforts, wiggling back and forth against the apron. Your sister simply sat there with her legs crossed and a smile on her face, taking a bite out of her meal every couple of seconds.
It took a few minutes, Heather almost finishing her meal but you felt your efforts began to pay off as the apron began to stretch and you heard a faint ripping sound.
The sound encouraged you and you struggled even more, just as Heather took a sip of her milk.
SNAP!
The apron finally snapped and you jumped free, almost stumbling onto the floor but you stood back up a second later. Heather choked and cough up a bit of milk, some of it landing on her large chest.
She stood up and placed the chair between you and her; knowing that she was in trouble. "W-wow Timmy, I didn't think you would break free. You've been working out?" She tried to compliment you to avoid trouble but you wouldn't let her off that easily.
You picked up what remained of her apron and followed it by taking off the rest of your clothes. Heather's eyes drifted to your exposed cock and you saw her lick her lips a bit.
"Say Heather, you said you like to dress up," You said as you took a step near her. "How about a bit of role play then?" You rushed her and Heather barely had time to scream until you were on her.
Later
You took a step back to admire your handiwork. Heather was on knees with her feet and hands tied up, the latter behind her back to prevent her from escaping easily.
"I guess those scout classes really paid off huh Heather?" You said as your sister rolled her eyes.
"Yes yes, I made a mistake so are you going to release me or," She seductively grinned and arched her back, thrusting out her front. "are you going to punish me like the bad girl I am?"