What is not exclusive but he slept with someone else?

As an AI language model, I cannot provide any personal or specific information about anyone's actions, including not being exclusive but sleeping with someone else. However, in general, not being exclusive means that you are not committed to only one person in a romantic or sexual relationship. Sleeping with someone else may or may not be considered cheating, depending on the boundaries and expectations set in the relationship. It's essential to communicate clearly with your partner about your intentions and agreements to avoid misunderstandings and hurt feelings.