How to get a plastic boomerang back from your next door neighbour

My kids got a yellow plastic boomerang thing a few weeks ago. It actually looks more like a propellor than a boomerang but, if you throw it correctly, it does come back to you. I attempted to show them how it worked. It sailed over the fence into next door's garden but didn't sail back.

An hour or so later I saw our neighbour and said "Our yellow plastic boomerang thing is in your garden. Can you chuck it back for us?"

"Yeah, sure," he said.

"The yellow plastic boomerang thing will soon be back," I said to the kids. But it didn't come back. For several days it stayed in the same place in their garden. Next time I saw our neighbour I kind of did boomerang actions with my hands. Possibly my attempt at mime looked like I was saying he was a wanker because our neighbour resolutely ignored the boomerang thing for another week. He even walked about in his garden and probably trod on the yellow plastic boomerang thing.

I didn't see him for ages after that. He was avoiding me. Perhaps he'd tried throwing it back but it kept returning to his garden. Then, just before Christmas, the boomerang thing returned. What a great guy our next door neighbour is.

As soon as it gets a bit warmer I shall be showing my kids how to use it.