I would tell her as a "Oh by the Way....please make sure you haven't keyed you phone by accident every once in awhile" You called my phone last night and when I answered it I only heard you and "Foxtrot Hotel" talking and giggling etc. I had to quickly turn it off before I heard it go to another level!!!
Also you said you would not initiate the divorce proceedings. Well she is in no hurry and FH isn't pressing probably due to his marriage situation. So are you going to live like a monk while your wife doesn't? If not then the lesson about marriage you have been teaching/showing your kids goes out the window. Just throwing that out there. You two can always get re-married.