I don't think you should take her GF's word only. I am always suspicious of a woman who tells this stuff on her "friend". Women are very different about friendship than men are. Why would her friend tell you all of this? I thought you had other proof that W was contacting OM.
If you can afford a PI to follow her...to know for sure about A, then maybe you want to consider it. All of that has to be your decision to make. What would you do if the PI confirmed the A? Would that be a dealbreaker for the M?
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!
