I agree 100% with treevoice. I also think you may need to keep in mind that your T likely has complicated feelings/thoughts about the situation, both as a professional and as MC's colleague (and technically his employee). It seems clear based on things that you've shared here in the past that you're protective of MC when talking to T, and it seems like you might make assumptions about what her opinions of the situation are, particularly given that she is (perhaps wisely) slow to share them with you. Add in the maternal transference and it becomes a bit of a powder keg.

I would proceed slowly and gently and try to lay out little pieces of it at a time, being very honest and deliberate about what you think and feel, and giving your T space to do the same. I do think this is a great topic for therapy, and I hope you get some useful insights out of it.