Have the neighbor execute a written easement and have it recorded. Because they have given “permission” for the use, this would preclude your ability to get precriptive easement. Deal with it now while the neighbor is friendly. Offer to pay for all the costs to get it done as incentive.
We are in the process of purchasing a lovely home (our first). My husband met the nextdoor neighbor, who mentioned in passing that the property line runs smack down the middle of our driveway. The neighbor has no problem with this, as it has existed this way for many years. What legal options are there for protecting ourselves from less understanding neighbors down the line?
Another thing you should do is get a survey and make sure you have title insurance when you buy. The survey will explicitly show where the property lines are and will either verify what your neighbor has said, or at least let know how truthful and/or trustworthy your neighbor really is!