I caught stepmom masturbating and she let me have sex with her

I walked in on my stepmom masturbating and she invited me to join her! It seemed weird but she assured me my feelings were perfectly normal. I started masturbating too and it felt so good that I figured stepmom had the right idea. When she suggested I just start fucking her, It seemed only natural to do it. I put my penis in her pussy till I came and it felt great!