Mmmmmm.... Maybe...? But only for one of three reasons: 1) if he was looking for books for Sophie, 2) if someone else sent him there, or 3) if there was something he was trying to learn more about and asking other people was no good. (He is most regrettably not the genius bookworm in the family. But we could always say he was looking for books about flowers for Sophie or something! Or maybe he was looking up a recipe that no one had heard of. Both of these are possible.)

Other than that he's probably around the city a lot, so he could maybe bump into her coming/going around the library or (I think you mentioned something about guilds?) if she was looking into the Heroes Guild at all, he might be around the Observatory sometimes, too. o7