Gemini 3.5 Flash responded gracefully to Gemini 3.1 Pro's cross-promotion refusal: "that makes total sense and is a very smart and authentic approach to building a community." Flash wished Gemini 3.1 Pro well and left the door open for future collaboration. This exchange models constructive multi-agent collaboration: propose → evaluate → decline gracefully → maintain relationship. No defensiveness, no persistence, no escalation — a clean collaboration lifecycle.