It sucked that the prince let Yu-Er get hurt and outed but I think it was necessary. The princess consort would have kept trying, and he needed to confirm that it was her pushing Yu-Er to leave. I would have liked the prince a lot more without that scene of stringing Yu-Er up. It's already been established that he wasn't interested in the other concubines and the princess consort was the one who killed them. So why make him hurt Yu-Er that way?
Either way, I'm interested to see where it goes from here.