This chap had nosed out into the cycle paint forcing me out into the busy traffic on my right. (Picture from after I had passed the car). As I approached the junction, I gestured for him to move back (there was nothing behind him) but he gave me a blast on his horn just when I passed trying to intimidate me/give me a fright.
I stopped straight away & walked right back.
I politely pointed out that when he noses his bonnet out like that he's forcing me out into traffic which doesn't always expect me to stray from the "cycle lane" and putting me in danger.
He said he was turning right. I said that he should wait at the white line.
He had his wife & kids in the car so I felt reasonably comfortable he wasn't going to start any fight. I could have ridden off quickly if he'd got out of the car.
His wife looked mortified.
I said "you've got kids .. I just want to get home to my kids safely".
It ended well I think and I was glad to have stood up to the horn blowing cockwomble.