Trying to be rational now my stance may be "i am not prepared to lie any longer about your affair or mine for that matter if anyone asks."
Grand pronouncement. Not a fan. Whatever you're going to do, just do -- don't talk about it. Don't go looking for trouble, but the next time someone you care about asks you a direct question, answer them honestly. Then when you get the inevitable blowback from your wife, you say "I simply decided that I'm no longer willing to lie to cover up your affair," and leave it at that.
Strong men lead with ACTIONS, not with grand pronouncements, which only come across as tactics and holier-than-thou.