Working out is an excellent analogy to healthy activity.
lets look at things this way...
Two kinds of activities... Healthy and Unhealthy
Healthy activities - Feels BAD doing it, feels GOOD later on
Unhealthy Activities - Feels GOOD doing it, feels BAD later on
Guess which one marriage falls into? Guess which one affairs fall into?
Your phone call.. HOw does that fit into this? I suspect the second... feeding that craving to hear his voice... you get that rush, but after the calls' done you immediately regret it...
Look at that phone like a giant piece of chocoalte cake when you are trying to DIET...
Marriage is much like dieting, and an affair is much like cheating on your diet, it feels good at the time, but you PAY DEARLY for it...