Then again, looking at your timeline (this has been going on since 2007???!), I'm betting that your husband believes -- by your ACTIONS (or lack thereof), not by your WORDS -- that you ARE pretty much willing to put up with this.
You can make all the speeches in the world, but our spouses will ultimately judge us by our actions. If your words say "I will not live in an open marriage," and yet you do nothing about his continued infidelity, then he probably doesn't take you very seriously anymore.