I've been there. Driving slowly through a busy Asda carpark to pick my sister up from the entrance.
I noticed a car put its reversing lights on so came to a stop. The silly bint started to reverse out and when I noticed she was getting closer and closer, gave my horn a few beeps followed by a longer blast when she wasn't stopping.
So she reverses straight into my front wing so I get out only to have her shouting "WTF are you doing driving into me????"
I just laughed and said are you serious, to which she continues to keep on swearing. I kept my cool and checked the damage. Nothing apart from a cracked indicator lense and the bumper mount was pushed in a little (didn't notice until a later date).
There was no way I was going to offer to give my details as she'd no doubt blame it on me. It just really peeved me off to have this stupid woman shouting at me when she'd reversed into me.
Because of her attitude I couldn't resist shouting "shut the **** up you silly woman" before I got in the car

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/Awaits flaming