Because they were doing work on your bathroom you asked your friend, Josie if you could stay with her for a few days.
Josie is a childhood friend from the old neighborhood, who is "just a friend" (you tried, but she wasn't interested in you).
Before you come over she tells you that her friend Maria has been spending the week with her, and staying in the spare bedroom so you will be sleeping on the couch in the living room.
Maria was staying with Josie because she needed a "mental break" from her boyfriend. Josie had causally mentioned that Maria's boyfriend was worried that Maria might be cheating on him because she was "over sexed" (he knew that Maria had a very high libido and wanted sex more often than him, and he couldn't satisfy her).
You remember this about Maria, and to be honest you were intrigued about what she would be like in bed. However, it was an awkward situation because you were a "guest" in Josie's house.
Oh well, anyway during the night you had to get up and go to the bathroom. Ironically, Maria was on her way to the bathroom also (she was in the bedroom next to the bathroom) so you let her go first.
You're looking at her body when she walked into the bathroom and she only had on a bra and panties...Damn. When she came out you wanted to say something, but you just smiled.
Nevertheless, when you came out the bathroom Maria was standing there and asked you for a favor. She complained about the bedroom being cold and that she was having trouble closing the window, plus she couldn't get the heat on.
First you closed the window then you turned the heat on (the radiator knob was stuck).
Maria "Thank you" with a big hug that lasted for the next 2 hours.