Do you and your significant other have "exceptions" in your relationship?

Whether they are spoken or unspoken, do you have any kind of “agreement” as to when it is acceptable to say, break the rules of fidelity?

I was just thinking about this because, for example, whenever my ex and I did ecstasy (ha, that’s kind of a pun) together, it was kind of an unspoken agreement that it was okay to kiss other people. I mean, duh, we were on ecstasy. We gave each other verbal permission, but we never had a huge conversation about it. I watched him make out with some of my good friends (girls) and he watched me make out with guy friends. It didn’t bother us at the time and there were no hard feelings in the morning. In terms of strangers of the opposite sex it got a little dicier, but I think we were into each other enough to to feel compelled to kiss anyone else. But strangers of the same sex were completely fine.

It’s just interesting, months—a year later, to deconstruct all of this. It’s kind of fucked up in a sense, but hey, we’re young, we were on drugs.

Anyone else have similar relationship rules/exceptions, either under the influence or not?