Since it only takes 5 minutes, just walk over there and trim it. If you
think they're really picky, ask one of them to come out and tell you if it's
done the way they like it. Of all the neighbor problems you could have, this
is like a .25 on a scale of 0 through 10. Don't make it worse. As far as
them "drinking your wine", you invited them, right? They probably figured it
would be good to broach the subject when everyone was loosened up a bit.

Shall I tell you about my neighbor, who thought it was OK to let their
ChemLawn moron hose down my vegetable garden with pesticides, and how I was
prepared to get an injunction from our town justice, which would've directed
the cops to arrest the neighbor if the spraying actually took place? That's
an 8 on the scale. A convicted child molester moving in next door - that's a
10.