Sounds manipulative.

If it was a deliberate "technique" intended to provoke a response, that is manipulative by definition.

If his mood swing was due to personal problems, then you are being jerked around by his own needs.

Therapists are supposed to keep their crap out if it, but if they do insert their problems, it is usually rationalized as part of "the work".

I have not seen that kind of bipolar behavior in a therapist, but i'd be wary if i did.

Some people find it helpful to be manipulated like this. I found it toxic.