Re: Say nothing or explicitly say I'm leaving?
Yea I see your dilemma. In this particular situation you need to leave without saying anything even though I know you'd rather tell her. Let me analyze for a sec and let me know if I'm right or not.
It seems to me that you telling her to leave would be your last ditch effort to get HER to make an effort with you or she'll lose you. Basically you're trying to get her attention. I been there buddy so don't beat yourself up. So I know you really really want to tell her you're leaving, but you really should NOT. Because you hope that it will knock some sense into her and let me tell you...it WILL NOT.
All it will do is let her know she has all the power in the situation and she will see right through you knowing you're trying to get attention. The correct response is to leave. But that doesn't mean it's the end. For now you need to date other women and get your head straight before you go after her again otherwise you'll end up right back here. Learn about building attraction and playing hard to get. Learn about push/pull and kino escalation. Then go back to her.
"All things are subject to interpretation. Whichever interpretation prevails at a given time is a function of power and not truth."