Ah the old orgy agony, yeah the only thing to do is to join in or just lose your mind. Either way your fucked Kek. Anyways Yeah its fucked up theresia had to see that shit, but now I don't know if she survives.
But why did the wife decide to hold a cult orgy and/or participate in something like that in the castle, the center of the Count's kingdom, where she knew her husband would be coming back to? It could be assumed that she just stopped caring at some point. I do wonder if she was simply brainwashed by that cult to hit the Count where it hurts, or if she betrayed the Count on her own accord.
Edit: Come to think of it, it's kind of unbelievable how they snuck that big statue inside the throne room like that.