They do these things because they feel entitled. They feel entitled because they feel like you have no other options. Like your best option is to be in a relationship with 20% of your spouse.
I am really starting to believe that its going to be crucial to have options. Develop them if you don't have them.
Remember, part of the formula of the cake is using the LBS as a "chaser". So the cake is more pleasurable while you are down and dependant upon them, it makes them feel more important. As soon as you take this away, there is no more cake for them. Hell, they may even feel like a sleeze once you have attractive relationship partners of your own.
