I sat on the couch with just my bra and panties on. 
The naked sub laid across my lap. I began slowly, testing the sensitivity of his bare skin. I learned how much he could take, when he would start to squirm, and the spot that felt sweet in my palm. I could feel his hard prick pushing into my thigh.
I started with light, quick smacks randomly alternating from cheek to cheek. I slowly increased the intensity whipping him up into a frenzy and at the very height of it I stopped the smacking and began raking my fingernails across his skin and let him relax back down into my lap. As soon he was settled back down I started in with the hard deep smacks. Each smack was intense enough to make him recoil on its own.
As his jumps and squirms turned into a humping motion I ordered him to get on his knees in front of me. I had him hold my feet, soles facing each other and fuck my feet. It felt so good having his hard cock sliding in and out between my feet! All finished off with nice hot cum shooting onto my foot!