To be really upset.

[Loveebug]

Was driving. Got to traffic lights. Heard a beep. I was going round, he was turning off when we set off. As I went he put middle finger out the window and shouted big nose twat or something like that. Nothing happened, no near miss. I don’t even know what set it off

Yes. It was not clear in the initial post that this wasn't at a two-lane traffic light. You all have those correct?

I would be inclined to forget about it, don't make his problem yours.
He's probably had a bad day at work, a row with his boss or his wife, who knows but some people are just wankers behind the wheel and it's the only way they know to release some frustration. 🙄

Meh, forget about it. People turn into idiots in their cars. A man gave me the middle finger earlier for letting an ambulance into the lane, delaying him for approximately three seconds 🙄

I had a guy stick his middle finger up and call me a c * * t! Why? Because he had to stop and let me past when it was my right of way on a two way street and there were parked cars blocking the road in front of him so he needed to come onto my side to get round them! It was SO unfair, especially as I gave a friendly way and mouthed ‘thank you’ for waiting…. Even though it was my right of way!! Five years on and it still rankles 🤣

He was a dick, there's no other explanation, no need to dwell on it. Some people just are.