I have a garden. Surrounding it is a large communal garden which is rarely used. On the other side of the communal garden are other people's large private gardens.
I am working from home, I am never usually here in the weekday. Upset about the lockdown but following the rules - I haven't opened my front door since I got back from a medical appointment on Saturday, am eating weird combos of cupboard food until I absolutely must shop again, etc etc.
A family from the other side of the communal garden, who have their own large garden, have decided to make full use of the communal one. I think this is a bit silly because other people will follow suit and stop thinking the rules apply to them, but I try not to get too het up about it. The mum also has an ongoing cough that I can hear through my closed windows.
I try to ignore and get on with working from home - I have no intention of going out until I need to, I am not using the communal garden so it's no skin off my nose, and I don't want to be arguing, it's a tense time for everyone. I sympathise, it's difficult to keep kids indoors in this beautiful weather (though am 
about why they can't use their own garden, like every time I've seen them outside at weekends etc).
The kids are shouting and playing over the last two days, I block it out. Until... they kick a ball which goes over my 6ft fence and thuds against my window. The kid somehow climbs up and looks over my fence but scarpers when he sees me.
A few hours later my bell rings. I ignore as I'm not expecting anyone. It rings again and I answer (on the phone) - it's the mum asking if I can throw the ball over. I say "no, because of this whole coronavirus thing", and she tells me to just wash my hands after. This annoys me so I say they shouldn't be playing for hours in the communal garden anyway, playgrounds around here are shut on the same principle... She says OK and goes.
I am now thinking she'll send her husband over to shout at me later 
Ordinarily I would have just chucked the ball back as soon as I saw it in my garden, but I don't know if I'm extra grouchy having to stay in while people all around me seem to be looking for loopholes. I'm not scared of germs, if I get the virus I get it, but it's the principle. I'm torn between a) just throw it back and stop being sour and b) maybe this is a lesson in community responsibility...
So, aibu to not throw the ball back? They'll probably climb into my garden to get it...