He had it coming though. Taena is obviously protective of Lyriel and when she asks him about them he blows her off?
Well, those dialogue options were either bad or worst to pick from, which was out of his character in my opinion. I mean I get he could get a little annoyed by Tea for dragging him down to basement and then trying to intimitade him there instead of just taking him aside to talk in private, but instead of simply saying "We're stuck in the magical house looking for a way to get out", which wouldn't be much, but would be far more better answer than any of given options.
Also, even if MC had it coming it doesn't justify Tea's actions. Hell, I would say MC was a dick to her just because instead of simply talking with him in somewhat private area she jumped straight to intimidation and interogation in a dungeon which she mentioned out of blue when they were walking down the stairs.
I know it's a assumption, but I wouldn't be suprised if drugging MC was also Tea's work to allow her and girls to talk out of Lyriel the "real" situation without MC's involvment into the talk and maybe helping her to run away. I mean girls really didn't care about MC hitting the counter with his head like it was bag of rocks dropped onto metal plate and Tea already skipped few steps, so why not to skip few more?