Well, if you have a bad back, are really tired, don't want to have to do any work...
there is something to be said for just laying back, relaxing (most of your body - lol), closing your eyes, and letting her do all the work bringing you up to the edge, backing off, getting closer, and so on for an hour, and then finally cumming. Or having it done twice...
We all love a good steak, but sometimes spare ribs are good too!