Hugh Hefner said something interesting. Go figure. It was in response to Tiger Woods' so-called 'sex addiction' for which he is receiving clinical/medical attention.
But Hugh said, "I think by and large it's a cop out. I think 'sex addiction' is a convenient phrase... Sex is not like a drug or alcohol. It doesn't affect the physicality in the same way. But it can become very obsessive. Neurotic people can do very foolish things. People make choices. Most people who cheat do it because they think they can get away with it."
Bravo. From Duchovny to Sheen to Woods to that other guy who's married to Sandra Bullock, I say, you do not have a clinical addiction to sex any more than me and everyone I know. What you do have is a disregard for / disinterest in fidelity and monogamy. You are egotists with childlike minds.
I watched a documentary on the development of a child's mind. They put down a small piece of chocolate and said, "You can eat this now, or, you can wait ten minutes and have this bigger piece of chocolate instead..." I can't remember the actual ages but it was something along the lines of three to six year olds ate the small chocolate straight away, but by age seven, they could reason enough to wait the ten minutes and get the bigger chocolate.
Tiger Woods, metaphorically, took the small chocolate by cheating on his wife each and every time. That's not 'addiction', it's just Hedonism 101 - instant gratification for short-term gain, unable to to calculate the long-term losses it will create - with a garnishing of Ubermensch.
I cheated on a girl once. I was 21. I used all sorts of excuses but in the end, it was because the 'other woman' was there, offering sex, and I took it because I was weak - not 'addicted'.
I have also been cheated on... twice. Both girls also used implausible excuses when the real reason for cheating was as simple as 'they wanted sex with that other person'.
Ricky Gervais, in one of his standup performances, talked about how someone wanted him to donate money to a charity that was looking for a 'cure' to obesity. He remarked, "Obesity is not a disease. Polio is a disease."
The same goes for sex. Wanting lots of it is normal. Hell, it's essential for our species' survival. Monogamy is a social construct, I guess, but it does have evolutionary benefits in that it provides stronger family units and by extension, stronger communities.
Monogamy is very, very difficult at times, and I understand that the likelihood of a partner cheating on some level, whether it be blatant rooting or even just feelings / desires for another person is high, but if you do cheat on your lover, don't use the 'sex addiction' line.
Drugs are addictive because they have addictive chemical properties.
Sex is not addictive, it's just awesome and more-ish.