Sex with someone now feeling bad

Last sunday I had sex with someone who is very close to my family. She is the wife of my younger brother. We were drunk and my brother was out of station. suddenly I felt her lying on my chest. She told me that from last 5 yrs my brother could not satisfy her sexually. After few moments I felt I was licking her pussy. I fucked her twice that night. Next day also I did 2 times. But now I am feeling bad and she continually asking me to fuck her as much as possible. She is very aggressive and even perfom rimjob