Jaberwok
No you're right, he shouldn't, but he was under enormous pressure to marry (think the abdication) and the late Queen Mother, and Diana's grandmother Lady Fermoy were extremely keen on this match. Unfortunately they certainly were not keen on a Camilla match. I'm certain that both parties tried to make a go of it, but lets face it, they didn't have one thing in common in any way whatsoever . Right from the start it was a struggle for both of them. Again easy enough to sseparate quietly if you are not in the public eye,but when you are as these two were, it becomes a nightmare. Thank goodness there wasn't social media at this time, the tabloids were bad enough, and the BBC loved it. It was a bad time for two very unhappy people, and they both fell in love with somebody else, Diana,several times, Charles just the once.
Charles was still in love with Camilla when he married Diana by all accounts.
Camilla chose to marry Andrew Parker Bowles. No one forced her. But when that didn't work out she wanted Charles. I think she behaved very badly and very selfishly.
But so do/did many of the Royal family. I doubt too many people look up to them anymore. They just enjoy the glamour and gossip.