Weapons training. It makes sense, to want to become more proficient in combat when one's team requires protection. Not everyone comes prepared - not everyone has Siebren's...particular situation. He listens, and ponders his reply when Seto pauses and then continues-

...oh. He had been correct, at least to some extent.

Siebren sighs and sinks a bit further down into the water, tension he was not aware he had been holding onto melting from his shoulders. "I am alright with conversation," he says after a few moments. "I simply...do not like questions, from those that do not understand."

Present company, it seems, excluded.