letschat,
What makes you feel that she is playing a game with you? Are you not doing the same? She enjoys the sex and so do you, that is all there should be to it. Are you in an emotional quandary? Are you getting a bit sentimental and miss her when she does not call? You need to handle this affair with maturity.
Remember you both are married and while you may be willing to disclose all about you and your family, she is not. The charm of such a relationship is the uncertainty and the edginess. The moment she reveals more, you will begin to worry and ponder and that will cause heartburn.
What seems to be bothering you, is that she knows more about you than you do about her. She has your telephone number and snap. How you get these from her during your passionate moments is a challenge that you should enjoy.
She has made it clear from the beginning that she owes you nothing and you should be prepared to face the disappointment when she walks away. Since she has being paying for her share of the fun expenses, I think this is obvious.
Do you have a different agenda from hers? Enjoy the sex as long as it lasts but do prepare for the consequences. There are two. One is when your wife gets to know about this sexual escapade and do not for a moment believe that she will not and the other is when your sexual mate, walks away. As long as you have your eyes open and a solution for both the problems, have fun.
