Well first I'd like to say there are a lot of guys who like the girl on top because that gives us a chance to really look at you and touch your breasts and thighs and such... As far as what to do... (after some foreplay).. just have him lie back, then straddle him and reach down and guide him into you... communicate while you start to ride him... ask him how it feels as you lean forward, or sit straight up... I'll almost guarantee that he'll be into it! In my experience, the only bad sex I've had with a girl, is when she just laid there on her back doing nothing... no sound, no movement. And don't forget to put yourself in the position that feels good for you! I'm most excited when I can see that my lover is getting off!! Good luck!