Start with foreplay, to get in the mood. Put on something he likes or throw on some cute panties and a tank top (bra optional). Do a nice strip tease.
Make sure he his sitting at the head of the bed leaning back on some pillows. After your dance, crawl up the bed and take his clothes off. Remember, make a show of it dance around, pull his clothes off with your teeth, do something.
After he is fully aroused, crawl up and sit in his lap making sure he is inside of you, sit back and enjoy the ride.
Enjoy for a little while and then sit up, raise your hips, slide up, and slip his moistened manhood in your rear and experience the pleasure with little to no pain.