A lacy black thong

You opened up the fabric and it was a lacy black thong.

"Erm... Sis, how do your butt even fit into this thing?!" you held it up in the air to show your sis. Then you put it in front of your pelvis to further demonstrate how ridiculously small it was.

"It's stretchable. If I can wear it, so can you. For goodness sake, bro, you're way skinnier than me! Your waist is 29 inches and mine is 30 inches!" Your sis said.

"Don't you have more normal underwear?" You asked.

"Not something that would fit you. Just suck it up and wear it. You looked like a freak with the boxer."

"I'm already a freak with a dress."

"Less freak without the boxer."

"Shut up and turn around." You finally said. Your sis closed her eyes and turned around. You also turned around and pulled down your boxer. You threw your white boxer on her bed and pulled the thong up.

Unfortunately, you weren't very well-endowed and fortunately, you managed to hide your penis under the tiny fabric.

"Are you done yet?" Your sis asked as she sensed that you should be almost done.

"Yeah." You replied quickly.

She turned around and she glanced up and down. She looked pretty satisfied because she can't see what underwear you're wearing. "I guess I could give you this set of dress and thong for tomorrow. If you still find the thong too small, then there's nothing I can do about it."

The thong does stretch and you don't feel anything after getting used to it.