Dorian glanced up, balancing a handful of books in one hand, teacup in the other - he was not expecting to see a young person there, with a dog no less, and one dark eyebrow lifted in a slow raise. But he didn't drop anything, to his credit, smoothly setting the books on a table with the rest of his things - the table he'd claimed for the time being - and approached a little, teacup in hand. The aroma wafed pleasantly; it was a simple black tea, nothing that would make him itch (he was allergic to stripweed, you see, but luckily had not seen it growing around).
"Avanna," he replied, accent rippling around the word smoothly. "Am I in your way? My apologies."
He didn't exactly have monopoly here, it was simply that the library was a quiet place, mostly uninterrupted - many of the live bodies didn't seem interested in all this, mostly just whatever whim tickled their fancy, so the building wasn't a place for social gatherings. Precisely the reasons why he chose to spend a lot of his seemingly neverending time here.