My cousin, a returning resident, had to stay at my place while looking for an apartment in Tokyo. When I checked the dresser for pajamas, I found my collection of panties. I jokingly offered her to wear one, but she refused, saying she couldn't wear such an odd outfit. However, the next day, she was wearing panties. "They're actually quite comfortable," she said. For the few days my cousin stayed, I couldn't stop getting aroused by her in panties, no matter what we did. Seeing me like this, my cousin started teasing me.