Thanks Diesel for bringing up one of the situations I find most uncomfortable. As soon as a client starts expecting more time, discounts, because you seem to be enjoying yourself is disrespectful and rude. One of my favorite comments, made a few times if I really got into the session or he made me go once or twice "Hey, you should be paying me!" Never said to me in a rude fashion, but even as a joke, makes me VERY uncomfortable. The money issue should never be brought up once the rates have been set. It only makes both people feel awkward.
Unfortunately, women remember those comments longer than the orgasm, and slowly, those little perks go away as the clock moves to the side of the bed.
Its hard with a GFE experience, as you tend to repeat and develop a friendship and a closeness, but you must never forget that this is a business. Drop the right amount of money on the counter as soon as you walk in (if she counts it in front of you, she's being just as disrespectful and rude). She shouldn't have to ask, and you don't want to come off looking cheap.
Always respect that it's a business. If you do, those little things you appreciate are her way of saying thanks, and they'll keep coming (and cuming, and cuming).