Sir, Please let me refund this XX!

Summary

“Could you show me how to use it? If you really don’t feel anything, I’ll give you a full refund.” Yoosung has never used adult toys. He went to an adult shop after being tricked by his unrequited love that he will date him if he gets a refund on Dildo. Contrary to the rumours of a scary-looking man owning the store, a handsome man named Jinwook appeared. Yoosung lies about his experience with the dildo, claiming it to be unsatisfactory and asks for a refund. Jinwook willingly agrees to do so without hesitation but under one strange condition... "Since there are many customers who lie to get a refund,we have our own system of checking the truth." Will Yoosung successfully get his refund?