My Wife's Best Friend Lives in My House

My wife let her best friend live in our house. But she suddenly had to go back to her parents' home for something, and asked me to take care of her best friend. Take care of? What kind of care... She fell in the bathroom and called me to come in and help. Late at night, she said she was afraid of sleeping alone and asked me to accompany her. I think something is wrong with my wife's best friend! This novel and its characters are purely fictitious. Any similarity is purely coincidental and should not be imitated.