He was locked up in the bathroom and left alone with his sister-in-law! It was cold so I was soaking in the bathtub together, but couldn't hold it in and fucked her all the way through the morning!

I heard the voice of my sister-in-law from the bathroom. "Help me! I'm locked up and can't leave!" It seems that the house hasn't been set up so the door to the bathroom has stopped opening. My brother is on a business trip and only me and my sister-in-law are at home. I had no choice but to open the bathroom door to help my sister-in-law... and it turned out! Even I've been locked up in the bathroom! My brother won't come home until morning, and I'll just be alone with my sister-in-law in the bathroom... No... don't think about anything strange...but...!