Curvy step mom surprises me while I'm pleasuring myself

After my father passed away, my stepmom moved in with us. She's a total hottie, and I'm not just saying that because she's my mom. She's got these amazing curves and a big ass that just makes me weak in the knees. One day, I was alone in my room when I decided to pleasure myself. I was so into it that I didn't even hear her coming in. But then I saw her standing right behind me, and my heart nearly stopped. She didn't get mad at me, instead, she showed me her tits and asked me to touch them. I couldn't resist. Then she took off her clothes and got on top of me, riding my cock like a cowgirl. We went back and forth, changing positions until she sat on top of me and let me eat her out. It was amazing, and I came so hard. After that, we had sex in different positions until she came too.