[stomachmonkey]

You need to get him to stop right now.

Don't allow him the adverse possession option.

If he is already unfriendly this is a real possibility.

If you don't think you'll use it then offer to sell it to him, (if you can subdivde that small a piece).

Why would you give it away?

And what are the potential liabilities for you when his street light falls over and injures someone or blinds a driver coming down the street causing an accident?