W, This is where I stand with OM or any other person. I cannot allow myself to be in a relationship where my partner chooses to engage herself physically or emotionally with another man.
I heard you say that you need space and time.
I agree and think that each of us should take time to allow ourselves the opportunity to figure things out about ourselves and what we want.
Strike the first line. It makes the rest of it make no sense. Basically you're telling her in the first line that you're done because she's choosing OM, but then in the rest you say you should both take time to think about it. Just tell her you both need space and time to think things through and leave it at that. There's nothing more that needs to be said at this time. Like uRworthy said, all she's going to see is blah, blah, blah anyway.
Reminds me of a Far side cartoon that went something like:
What humans say: "Fido, go get the ball! Go on Fido! I threw it over there! Go Fido, get it!"