QS she has a void in her fright now... distance in marriage creates a void.. oftentimes people fill that with a person and that's how the infidelity starts...
your wife's obsession is to fill that void
The thing is, she can fill that with something healhty like a gym membership or rock climbing or volunteeer work.. but she's looking for destructive avenues because the payoff is quicker and more exciting...
DOn't be surprised if she starts shopping heavilly or drinking more