He's pretty big

Reverse Cowgirl Position
How to do it:

He lies back; you face his feet and lower yourself onto his penis with your knees bent and your calves folded toward him. Hang on to his thighs for support as he lies back and relishes in the steamy sight of your bottom lifting up and down and swinging from side to side before him.

Why you'll love it:

No face-to-face contact means you can feel but not see your partner, which is fabulous for fantasies. You can either sit up or, if you’re feeling naughty, lean forward, resting your weight on your hands to expose both your vulva and anus. But be careful: Leaning forward too enthusiastically will leave both of you feeling oddly empty. That’ll be because his penis has popped out! Also note that this one’s more for him than you -- there’s a visual feast for him but little in the way of clitoral stimulation. On the other hand, turning him on so much is a huge turn-on for you!