re: What would the OT do: Neighbor problem

A moat is the only logical option.

Or tell him you know a gay older man that you'd love to hook him up with. If he denies being gay, just laugh it off and keep pushing that you totally accept gay people and you think it's great that he's gay. In fact, start referring to him as Gay-___. When he comes over say, "Hi Gay Eric." (only if his name is Eric otherwise he'll think you're dumb.)