Ok....every cloud has a silver-lining in this plot then doesn't it?
Either you get Edward to cheat on Bella with you...and Bella never finds out!!!!

Or.....
You try to get Edward to cheat on Bella with you....and Bella finds out and beats the crap out of you and you have to go see Carlisle!!!! SCORE!
Anywho....it'll probably be a tad different when Renesmee's all grown up. I mean, she's gonna go through the rebellious teen stage! LOL
That'd be AWESOME!
Then Edward + Bella can be like
'Meh, we tried our best.'And Renesmee can be like:
'Hmmm, what'll really piss off Mom + Dad? I KNOW! Let's go make-out with Uncle Jake!'Then she'll like it! Then everyone will live happily ever after! =P
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"He was a fool to think you could survive alone. I’ve never seen anyone so prone to life-threatening idiocy"
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Alice Cullen
'New Moon'