But that's the problem - most wives never meet the 'whole person' until many years later. If they had, they might have made the decision not to continue the relationship and spared everyone this heartache. Read the thread in Loved Ones asking GGs if they'd have married their H if they'd known all the facts about his crossdressing. Most, including myself, said no.
So are we wives really selfish? Or did we just never get the opportunity to choose the spouse and life we really wanted? That's an incredibly confronting thing to realise after many years of marriage. I don't know much about Leigh's situation, but if she came out to her wife after many years, then her wife's identity must be shattered. As now is Leigh's, by permanently purging this side of herself.
There are no winners here

But, as Sara Jessica pointed out, full honesty at the very start of a relationship usually prevents this situation.