have you ever cheated in a relatioship? if so why? was it worth it? did you confess or keep it discrete?

I haven't cheated. The reason, in addition to the fact that I strive to live an honest and noble life, is I haven't found the need. With the exception of my first serious relationship, I've always maintained poly and/or open relationships. I have engaged in acts that have made a partner uncomfortable, but each time it has been because we hadn't yet set boundaries, or because they didn't mention they were uncomfortable until after the fact. In most cases, simply communicating how they felt would have resolved any issues.
On the other hand, I have been cheated on by various partners and to varying degrees. Each and every time their actions were dishonest, and in most cases completely unnecessary. Lying is not acceptable, I cannot think of a situation in a mature adult relationship- particularly one claiming to practice "responsible non-monogamy"- where cheating would be acceptable. Being cheated on is not a good feeling. It is particularly unpleasant when a partner had to practice layers of dishonestly to do so. Interestingly, almost every time I've been cheated on the person in question has also disregarded their (and therefore my) personal saftey while in the act; disregarding safer sex and/or safer BDSM practices. It seems not to be a coincidence that these things go hand in hand.

Step right up...