Have him spread his legs, and use your feet to play with his cock and balls.
Make sure he is teased sufficiently. Try to get some precum on your foot, then ask him if he'd like a taste of you.
Tell him that he will have to earn it first by licking your feet while you play with your pussy.
Make sure to tell him to lick his precum off your foot.
Tell him he's a good cum slut, moan a bit, let his feet licking turn you on.
Tell him that you can't wait for him to swallow cum.
Have him thank you for licking your feet.
Rub his cock some more.