But can you pick your friend´s nose?

There are a few things that I´ve noticed are socially acceptable in Peru that are not nearly as accepted in the States. Public urination and defication certainly stand out, but I really only see that happening once or twice a week. The one that I see happening every day, however, is the nose pick. This isn´t just a nose scratch that could be mistaken for a nose pick either. I´ve noticed that many Peruvians are quite the gold diggers and will pick their nose at any time and any place. The other day I turned around to face my class after writing something on the board and one of my students had his finger so far up his nose I thought it would surely get stuck. It didn´t seem to matter that I caught him red handed (I´m sure there´s a joke there somewhere, I just can´t put my finger on it...), he had no shame. Then again, it seems to make sense. 97% of public restrooms (and even many private ones) have no toilet paper (or a seat for that matter, I´m a champion squatter now) so where can I expect them to get a tissue?