Nothing wrong with exploring new ideas and relationships. But you are starting with very incompatible people. Robert takes her vow of chastity seriously and would have to abandon that for one, not to mention she was once male and I see little chance she would adapt that far.
Robert is a better priestess now who cares deeply for her flock and is redeeming herself. Why throw that away?
It's not that I'm saying its a bad Idea just that its hard to make work. Few ideas are bad ideas ;)
