(You're quirk is called "Jump Cut". It allows you to slice cleanly through any material within a 10 meter radius. It's very dangerous, so you enrolled in UA under the support program. Ever since then, Mei Hatsume has been your senpai. She's overly comfortable with pretty much anyone in the school, but with you, it's another level.)

One day you visit the workshop after school and ask her if she can make a device for you that lets you control your quirk easily. She seems very enthusiastic about helping you. She takes measurements and gets to work. 30 minutes later, she seems to be struggling trying to turn something with her wrench. You walk up to her and ask her if she needs help. She declines, and 2 seconds later, oil sprays on both of you, on your clothes. Mei doesn't seem too bothered though.

"Dang it! Oh well, that's why we have washing machines in here!" She smiles while taking off her tank top, letting her large breasts jiggle out. She wasn't wearing anything underneath. Then she removes her overalls, leaving her in just her panties. She walks up to you and asks for your clothes. You strip down to your underwear, she takes both hers and your clothes to the washing machine, her ass jiggling with each step. She chucks it in there and sets it on heavy duty.

Minutes pass, Mei continues working despite her current position. You start feeling awkward, and ask her if this is okay. She just brushes it off.

"Nobody will see us, anyways. It's just us two! I locked the door. Plus, I'm 98.2% sure that you won't try anything funny on me, hehe." She drops a bolt and gets on all fours and crawls under the table to retrieve it, her huge ass swaying side to side.