I have completed the banquet. Went to Pothos shop. Apparently, I am suppose to ask him about his "secret". No such choice comes up in the conversation. How do I trigger the event or is this a "bug".

Note: I managed to figure it out.

Thanks.

In case anyone else is wondering about this (as it's a common hangup) - you can't ask him about his secret until someone else has suggested what it might be!

And then only after a specific event occurs. Be patient. You'll know when the event takes place.

Indeed. While Black Gate is a free and open world, SI is more like a huge play in which you interact with scripted actors who say their lines only when it fits the script.