One of the tricks is figuring out how to learn deep inside that you aren't in competition with her lovers any more than you're in competition with her friends.
It isn't easy at all. I'm struggling with it the evening... again. But it's less than normal, so there's hope.
Me: 40 straight male in a V with
Wife: Kay - mono female - married 18 years
LDR girlfriend: Susan - poly female - 3 year relationship
Stakes - very intimate friend
Ironically named Farmgirl - local interest