All what I remember is that a fat man (like John Goodman) sitting on a bed and asks a blondy woman standing away from the bed (i guess she's a lawyer in the movie) to lift up her dress or skirt, then she asks him if that's enough but he says more, more till she takes off everything, and then he has sex with her (I guess that she wants him to pay her or something). After this scene, she starts cleaning her legs.
I think that this movie was made between 1990 and 1997, it is not a porn one but only has a scene.

I have been digging in IMDB for a week but in vain :-(