I must be incredibly lucky because I have never in my life had anything leak, spill, ooze, or squish inside a purse. We are talking many years and countless purses. I do like Tokibebe does, I just shake it upside down to get out any crumbs or bits before I put it away.
I do keep all cosmetics in a cosmetic bag, but I always have a retractable pen floating around loose. You guys are freaking me out about the wayward pen, I must catch and contain it before it can do any damage:wondering!!