Quote:
let her go.
encourage her to go.
then go out and do something else with other women.
This.
What guys tend to not understand about jealousy is that over-protective behavior will NEVER stop a girl from cheating. If a girl has a low interest level in you and she finds herself attracted to another guy, she WILL cheat on you if she has the impulse to do so and is able to let go of her moral drapery. No amount of painful bondage will EVER stop a girl from cheating on you.
The ONLY thing in the world that will keep a girl from cheating on you is a high interest + investment. She needs to BE AFRAID that if she cheats, she is going to lose you. If a girl sees you as an Alpha, then theoretically, there is no reason for her to cheat. A girl has no motivation to cheat on LESSER alphas; only men seek variety because we were made to spread our demon seed as far and wide as possible (think back to biology).
Jealousy is a sign of insecurity, lowering a girl's perception of you. Which means, jealous behavior is almost INVARIABLY harmful to a relationship. If it lowers her attraction for you, it increases her chances of cheating on you.
I say "almost" because it's still necessary to draw the line. But this doesn't mean you complain about what she's doing - drawing the line means having a personal boundary and dumping her if she crosses it. You don't bitch and whine about anything, ever.