I'm thinking of spitting all over the produce in the farmer's market.
Why do you want to spit on market produce?
I want to have all the vegetables to myself
You are being selfish by destroying the produce at the market just so others can't get any. There is more than enough produce to go around for everyone, you should just buy what you need and not destroy it for others. You are spreading germs and disease by spitting on the food in public.
It's harmless to do this. I'm not sick.
You wouldn't know if you were sick. You could be asymptomatic without knowing it. Besides, it's still disgusting.