Unfortunately, some women allow GF's to have a huge influence on their immediate actions (like hooking up with OM and ruining their M). You'd think once out of high school that mess would stop. It would not be surprising if GF made your W think she had to choose between you and the GF! That was usually used as a last resort if the weaker person started pulling back and not doing what the stronger one wanted.
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!