One night and two days of 1 night and left alone by my wife's sister who suddenly came over

Tatsuya felt a bit lonely in the untidy house. It's been a few days since my wife returned home from pregnancy. No matter how used to living alone, one person is still lonely. I wondered how long this life will last... I was feeling depressed when my sister-in-law, Yuri, came over. Tatsuya was excited by the scene of dinner that wasn't alone for the first time in a while. There was no way she could have thought that Yuri would come to relieve her frustration. Yes, until Yuri burst into the bath...