Stepson surprises stepmom with oral creampie

I was laying on my stepson's lap, when I started to feel something hard pressing on my face. I opened my eyes and to my delight saw that he had an erection from me lying there! I wanted to be sure to make him feel good, so I didn't move when he put it in my mouth and I tried to pretend I didn't notice so as not to spook him. I wasn't expecting him to actually finish inside my mouth, but he completely filled me with his cum! It was a lot better-tasting than I expected - maybe I should lay on the couch with him more often...