Married for 21 years, actively cheating for the last 5. Have had two long-term partners and three short-term (and some have overlapped). Not cheating for the extra sex, cheating for other emotional reasons--which makes it harder since most men are just out to get laid, but I'm fortunate that I have found a good guy who gets it. Simply put: the marriage is over and I'm not willing to officially end it.
Yet.
Update: I filed for divorce about 6 weeks ago. I guess I'm the rare one who wasn't cheating because I just couldn't get laid at home, on the contrary I could've gotten some cock every night of the week but I just didn't want it. From HIM, I should add.
I know for a fact that I did the right thing by filing for D. I'm looking forward to living an authentic life. Sneaking around and screwing others and just generally having this secret life that your Spouse knows nothing about is no way to conduct a marriage.