"I'm beginning to find this conversation aversive, and I'm not sure why. I propose we hold off until I've figured that out."

I read this suggested line and felt a little worried. I hope rationalist culture doesn't head in that direction.

There are plenty of times when I agree a policy of frankness can be useful, but one of the risks of such a policy is that it can become an excuse to abdicate responsibility for your effect on other people.

If you tell me that you're having an aversive reaction to our conversation, but can't tell me why, it's going to stress me out, and I'm going to feel compelled to go back over our conversation to see if I can figure out what I did to cause that reaction in you. That's a non-negligible burden to dump on someone.

If, instead, you found an excuse to leave the conversation gracefully (no need for annoyed body language), you can reflect on the conversation later and decide if there is anything in particular I did to cause your aversive reaction. Maybe so, and you want to bring it up with me later. Or maybe you decide you overreacted to a comment I made, which you now believe you misinterpreted. Or maybe you decide you were just anxious about something unrelated. Overall, chances are good that you can save me a lot of stress and self-consciousness by dealing with your emotions yourself as a first pass, and making them my problem only if (upon reflection) you decide that it would be helpful to do so.