Wow - so sorry you are going through this. I'm sorry, but it really does seem that this is a "recipe for disaster"...to go from what sounds like a co-dependent type of relationship to "I need to sort out how I feel about my ex" to going out with a group of macho military guys - Whew.
You mentioned going out to a movie she generally would not approve of (strip clubs and nudity)...have there been any other personality changes that you have noticed? Is it possible that your wife has bipolar disorder? Have there been other times in her life (prior to you - may have been years ago) when she has experienced weeks or months of behavior that was out of character for her?
Bipolar people in manic phase can exhibit poor decision making, hypersexuality, disregard for consequences, increased energy/decreased need for sleep, hypersocializing, irritability, racing thoughts, reckless behavior, melodramatic statements, distractibility, etc. (although not necessarily all of these). Often bipolar people have been diagnosed with depression at some point in their lives (because depression phases tend to be more common as well as more distressing to the person than their manic phases). Just a thought.
Me: poly bi female, in an "open-but-not-looking" Vee-plus with -
MrS: hetero polyflexible male, live-in husband (23+ yrs)
Dude: hetero poly male, live-in boyfriend (4+ yrs) and MrS's best friend
Lotus: poly bi married female, "it's complicated" relationships with Dude/JaneQ/MrS (1+ years)
+ "others" = FBs, FWBs, lover-friends, platonic G/BFs, boytoys, etc.
My poly blogs here:
The Journey of JaneQSmythe
The Notebook of JaneQSmythe