You know what you should do. It may seem hard to walk away from something you know so well.. and even love... but if you keep letting her come back and try to justify it, you'll only learn to hate yourself.

Fight fire with fire.

My suggestion would be to get some crazy buddies together, get a hotel room with some strippers/hookers and have a the time of your life. Then, should you ever feel like getting even... show her the tape, lol.