I don't believe that he's a kiddie-fiddler or a sex pest. If he were, there would be an awful lot of me-toos coming out of the woodwork by now. No need for raping, he's royal, he wouild have beating off Amandas and Penelopes with a shitty stick.
As he was a single bloke at the time, why not just admit giving her one? He had no reason to suspect that she'd been coerced.
He's just an arrogant and spectacularly stupid man.