Phantom mother, the best mother-in-law

My father married a very beautiful woman named Misora ​​five years ago. Her father is completely in love with Misora ​​and is flirting with her no matter where he is. But I found out. Misora-san is not satisfied... Since then, an immoral feeling has arisen in me that I want to do something naughty with Misora-san. Then, when the two of us were alone, I looked at Misora's body while she was washing the dishes...