You can reset any repetitive behavior by not talking to the NPC for 48 ingame hours, which will clear out the short-term memory.
Unfortunately I think it's just part of how the Gemma-2 is working, I never had this with Nemo for anyone, and with Gemma-2 after like 3 or so prompts with anyone it starts offering me like 2 or 3 suggestions for paths in the conversation, "Do you tell them, or do you act mysterious" kinda stuff.
Edit: Actually started a new game and this hasn't popped up YET, but in that one save everyone started doing it, maybe I should avoid everyone for 48 hours on that save?