The accidental double meaning that ended a conversation

Person A asks: 'You probably already knew, right? I have a small capacity [속 좁은 거 = petty/narrow-minded].'

Person B replies: 'How would I know that? You haven't even put it in yet.'

The joke: '속 좁은 거' literally means 'narrow inside' — but Person B interpreted it as talking about a container or box ('you haven't put anything in it yet, how would I know if it's small inside?'). The response is completely innocent but reads as wildly suggestive out of context.

Person A's only response: 'What did you just say?' 💀