You're a 6 and she's a 9? Huh?
Your wife sounds deep in the throes of New Relationship Energy (NRE). She's known this guy a while but actual in person sex is new. NRE can make one make dumb decisions. Search for NRE here - there a lot of threads about it.
And then bring it to her attention again.
Tell her what is happening from your point of view. Do so when you can be calm and collected. This is not the time to blame - that's counter productive and will just cause her to continue to be defensive. Tell her how this affects you - give specific examples - in a non-blaming, 'I feel' statements. Ask her to work with you to find ways to 'even' her out. Make it clear that you are fine with this arrangement and are not seeking a way to end her seeing him. And gently but firmly tell her how this is negatively impacting yoru relationship. If it is impacting other family members (do you have children?), describe that too. Make it clear you do not want to leave, and do not want to end her other relationship - but you need her help to cope with these changes.
It might take a while before she can confront this in herself. Patience and care will likely serve you well.
Has she cycled like this the entire 4 years they've been meeting? If this has been going on that long, there may be something more wrong than just ramped up NRE (long distance can extend how long NRE lasts - the usual estimate is 6 months to 2 years). That shades into obsession and some more concerning possibly mental concerns.
Last edited by opalescent; 04-04-2014 at 03:26 PM.