I'm also married, so if that's a deal breaker, thanks for your time, and good luck on your search!
Still here? My wife and I are both joyfully exploring open, honest non-monogamy. This doesn't at all mean our marriage is going away. It isn't. I think labels only go so far, but the one that gets used for this is polyamory. I know it's popular these days, but that's only because it's awesome.
So just to be clear, though, I'm not especially looking for casual sex. I don't have the inclination, temperament or time to be promiscuous, despite having heard wonderful things about it. I'm hoping to make real connections and have some adventures (and not just the bedroom kind) but in the end I'm looking for more of a heart connection.