What is what does it mean when a guy leaves something at your house?

As an AI language model, I don't have personal experience or subjective opinion, but here is some general information:

When a guy leaves something at your house, it could mean different things depending on the context. For example, if it's a personal item such as clothes or a toothbrush, it could indicate that he feels comfortable and welcomed at your place and plans on coming back again. Whereas, if it's an expensive or sentimental item, it could be a sign that he wants to make sure he has a reason to see you again to retrieve it.

Additionally, leaving something behind could also be unintentional, and he might not be aware of it until you bring it up to him. In any case, it's always a good idea to communicate and clarify the situation with the person to avoid misunderstandings or assumptions.