Originally Posted by Kirbyman01
One issue I find myself having when writing is explaining how the main character knows certain things they otherwise wouldn't in context. Like them perfectly describing breast size or penis length, to also things like clothing and such.
Short answer: you don't. For bra size, you might get away with comparing what they're seeing to what they've seen before: "Her tits looked to be the size to wear a 34-C, like my ex-wife's did."
As for penis size, well, unless they're seeing the guy's wang through his clothing, there's no easy way to tell, is there? Save it for when he drops his shorts. (And even then, keep it general, unless they're going to whip out a ruler at some point.)
Clothes are easier, if you're simply describing what they're seeing. But unless the MC is really up on that sort of thing, stay away from describing them by designer labels and like that. But you could say that she dressed in the style of some celebrity reference point that the reader could relate to.