Forced restraint can lead to a super-hot session.
How To Do It
Lie back on a large exercise ball (or beach ball), your legs spread, feet flat on the ground, head arched upward, and fingers reaching toward the floor for support. Have your guy kneel between your legs and enter you. He can continue kneeling while holding your hips as he thrusts or he can stretch his body over yours and support himself with his hands on the floor in a push-up position. Grab his butt and draw him into you or keep your hands on the floor for balance as he moves in and out.
Why He'll Love It
The exercise ball will roll out from under you if he thrusts too hard or too fast, so your workout partner has to restrain his motions - no wild bucking - which will keep his desire on a slow, super-hot boil. Also, maintaining your balance will force you to tilt your pelvis upward slightly, so he'll experience intensely deep penetration.