@Leora85 Sooo here's an interesting thing - I got Cassandra to mention Dorian to Bull, so I ran through the end of the game to check, and Dorian acknowledges being in a relationship with Bull! I am certain their lock-in dialogue never played, nor did I ever have the option of speaking to either of them about it. On top of not being able to speak to Solas about our break-up, I'm thinking maybe I have a follow-up bug? Absolutely bizarre, but there it is, working (kinda).
