Nah he ditched her cos he was going to sea for 8 months. They'd only been together about 6 months and she was still officially with APB throughout, but he was billeted in NI for a while so they were on a break and she was free to see other people. APB had been a total cad but she was still crazy about him.
So Charles got an opportunity to date her, but then he was being sent away to sea for ages, and he was only 22 anyway, so apparently he never said anything serious to her.
Meanwhile APB got wind of C dating Camilla, clearly thought "fuck, better batten down those hatches", and once transferred back to England promptly proposed. This was only about 3 months after Charles left for sea.
She had been dating APB for SEVEN YEARS (!!!) by this stage so was very relieved and said yes pronto.
Apparently her mother was very dubious of the marriage as he was pretty shitty as a boyfriend. He was even shittier as a husband.