Have you checked out Demi Moore's movie STRIP TEASE? She does it all in that movie, where she plays a stripper and an older Burt Reynolds(?) is one of her older clients.

A Lap dance is basically what they used to call "Dry Humping" but set to music. As a woman, you will sit on him, eventually, and grind your pelvis on his crotch... all while looking him in the eye, holding him or caressing him with your arms and hands...and eventually, you bring him to a climax (= a HAPPY ENDING, that's what it's called) or your own climax - or you can do the usual, and just get up when the music ends, and leave him to beg for more of your ATTENTION

At that point, in a strip club, the client pays for another dance ... or for OFF-the-Book services. But usually, it's just more lap dances... for about $20 a "dance" until he's satisfied or he's out of money.

And of course, it pays to be wearing SOME clothing, but as revealing as possible... so it gets him in the right "mood".

Good luck and many Happy Endings, for Both of you