He's insanely hot and handsome, definitely straight though and I think as he's 18 he's struggling to feel comfortable posting NSFW content he feels ok with. I would prefer he was just upfront about what he's comfortable doing, over-promise and under-deliver.
From both the bulges and what's been said here sounds like he's reasonably hung, not a monster or anything but nicely above average. Since he's British almost certainly he will be uncut, is pretty rare unless for religious reasons. As he's 18 he could still grow for a few years too, fingers crossed.