Does anyone know of a way to stop our puppy going into our neighbour's garden?
Our neighbour has a dog too and this is what is attracting our little feller, he wants to play... but for some reason the neighbour doesn't want him there, (he doesn't poop or pee there or anything like that) There is a fence up already between the two properties but he's still small so he can climb under it.
Yesterday, he was really drunk and made an abusive loooong phone call threatening to call the police etc..., then he sent texts saying he was calling his lawyer and blah drunk blah... I know he can't really do anything about it but this morning the pup went to theirs and when my son went to get him, he threw the pup at my son

We live in the countryside and although there is the fence between the two properties, nothing else is fenced, so there are lots of ways for him to get to their property. We don't want to go to the expense of fencing everything in, and anyway we like the open space around us.
Is there some way of discouraging the pup from going there? A repellant scent or something else? I'm afraid our neighbour will hurt him, he's already tied up (on a very long leash) when ever he's in the garden, the poor little thing...