Hmmm, I have a couple of cents to throw in here. One thing about talking with your significant other, like my mom always says (although I don't think she would have pictured this particular scenario : ) .... write it down first, then you don't get your words mixed up and it's harder for the other person to misunderstand you.
As for whether something is cheating - I agree that it depends on the people involved in the relationship and no two will likely be the same, BUT one thing that I haven't seen mentioned is thinking first "How would I feel if it was reversed?" I know a lot of the guys in general don't see watching a stripper as cheating, but I'd bet they wouldn't be really comfortable if their significant others were hitting up the Chippendale's. That's it, just think how you would feel if the situation were reversed. Pretty simple, really.
By the way, good quote Sir Russell : )