she has gotten in great shape and been hitting the tanning booths....and looks great
Find the reason for her wanting to look young, fit, and pretty.....and you'll find the answer.
Are you sure she never discussed how unhappy she's been, or make complaints about you? Some women "try" for years to tell the H....but he's deaf and blind to what's she's trying to get across. Then she shuts up and he thinks everything is okay. Then the bomb hits.
It is not about what you feel should work in your M. It is about doing the work that gets the right results. Do what works!