My mom walked in on me.?

She walked in on me while I was masturbating. I couldn't help but become more aroused as she stood in the doorway watching me stroke myself. I didn't stop, I couldn't stop because I was about to explode. As I let loose all she did was smile as it dripped all over my hand and d*ck. She came into my room kissed me on the cheek and said good night. I can't stop having these lustful thoughts every time I see her. Can anyone tell me if this has happened to them before or if these feelings are normal?