A guy who decided to close his eyes on such topic once, now three years into the relationship.
The very reason you’re writing this is because emotions ain’t math. You don’t truly care what official labels, strictly logical exclusivity criteria or any other hoo-ha applies. You feel misled, even if nobody deliberately misled you. You feel betrayed even if no one planned to. The worm is inside. And it won’t stop eating from within.
It’s unfortunate, but don’t intoxicate your life. Run. She may be all the greatness in the world materialized in one living body, but the things ALREADY happened. It’s not a new person, it’s the same person still.