Question:

Maybe he acts young *as far as you have seen him*, but (and I'm sorry if I missed this) sitting down and having a coffee or dinner with him - what's he like then?

in my experience of males in their early 20s they often don't do so well in the first impressions game. Maybe nerves or inexperience at hitting on a chick properly.

as for the age thing i have got ID'd in the supermarket buying wine and i'm 28 (our drinking age is 18 here) so i understand looking young (although in my work clothes i dont think i do lol ... ah well it's a compliment )