Calm down, Michael now. The man is not of this planet, what with his wacky, bee-in-bonnet views on architecture and his questionable running of his vast estates. He's reached near-retirement age with nothing to do (except walk down lines of cheery fenced-in natives, waving and asking "and what do you do then?" because Mumsie has hung on for so long. He treated the feckless ingenue Diana like merdre from the night before he married her, and he reckons he has to be seen to be doing something or other that looks beneficent-ish. All-in-all, "twit" is a fairly mild way of characterising someone from whom a few decades of silence would have been welcome and who I'd personally reserve a stronger word for. Perhaps, in the cause of economy, with just one letter different.