Back in the day, when we actually used to spend time in our offices, there was an agent in ours who claimed that each and every client belonged to him.
"That's my client... I met them at the farmer's market... My daughter introduced them to me... we talked at our open house... I've shown them several properties..." you get the idea.
One day, this agent was sitting at his desk, close to the front of the office. He saw a lady walk into the office, and walk straight back to a female agent's desk, sit down and begin chatting.
He stewed for a while, trying to remember where he'd seen that lady before... and suddenly he had his 'aha' moment. He "knew" it was his client, and she was 'cheating on him' with another agent.
He picked up the phone on his desk, and dialed the other agent's phone. When she picked up he immediately made his usual claim: "That's my client you're sitting with!".
She calmly replied "Hmm... that's very interesting... since she's MY sister!"