Why do you need or want to tell your sponsor anything about your ex-T? That is something within your boundary. How much is relevant and important as a sponsee to share with your sponsor? Yes, you are concerned about feeling attached to your sponsor and the relationship with your ex-T was addictive for you, and it's probably important to share with your sponsor things about other addictions, to an extent. But do you need to go into the full details? The ending of the relationship was complicated. I think it ended because your T overreacted, not because you crossed her boundary. There are multiple ways to see the reason why it ended. It seems to me that the important thing is that the relationship had been what you now recognize as addictive, and it ended, and it was very painful for you. Would something like that feel like enough to tell your sponsor, if you want to?