Thanks for your feedback. It's interesting to hear of this from the other side.
As the "secondary", I feel excluded from their lives quite often. They don't want the world to know and their reasons are valid, so I respect that. But it does suck sometimes. I have asked him if he struggles with it, keeping someone he loves a secret from the world. Wouldn't he wish I too was there beside him, meeting his friends, sharing in the fun? He says he dies. It's hard.
In your situation, maybe it's her way of guarding her heart. The way I wish I'd guarded mine sometimes. When you're solo and on the outside looking in and the couple that you are involved with, despite what anyone says, at times it's a very scary, lonely place.