...to open my neighbour’s parcel (flowers)?

[WildebeestH]

Yesterday morning I took in a box of flowers for a neighbour. It’s not a close neighbour (over the road and slightly round the corner) and I’ve never met them before. I went round last night but there was no one in. Today there’s no sign of life and the curtains are closed like they might be away. Would IBU to open the flowers and pop them in some water? The box is light so I’m sure there’s no water in there.

What if they arrive home though, and see a card which states they’ve been left at your address though?

Good idea (though originally I thought this was a TAAT)

Yes, I would.

I would and then put a note through the door explaining that you have tried to make contact and didn't want them spoiled.