It sounds like you are all out of trust and tired of the lies. If you can't trust and believe someone than why would you want to build a life with them?
As far as the sponsor goes, if he has a good sponsor they won't share much of anything with you anyway. They should listen to you but that should be about it. A sponsor/sponsee relationship is based off respect and trust for each other. If your boyfriend's sponsor were to share information with you that he was told in confidence than that relationship would be ruined.
My last weekend of drinking was really bad. I have no memory of it but my family checked on me and they were so upset they took my phone and called my sponsor. He told them that the only advice he can tell them is that no matter how much they love me, it won't fix me and it won't make me stop. Only I have the power to stop and that won't happen until I experience enough misery that I will be willing to go to any lengths to feel better. He also told them to attend Al-Anon and if they are worried about my immediate health to call an ambulance. Otherwise he said all they can do is go home, say a prayer for me, and get on with their lives. Sounds tough but it's true. I stopped drinking 3 days later and have been sober for over 5 years. My family told me some of what happened and that humiliation and misery was enough to make me want to change. I hope your boyfriend finds that same misery so he can change his life.