I wouldn't think of borrowing my sister or my friends' bag... I would complement their bags but never thought of borrowing them - and I think they think the same way. However, if I really do ever encounter anyone asking for that, it would depend on who that is and the bag's value (either $$ or sentimental). For instance I'm fine if my sister's borrowing a bag from me, not only because we're close but also she handles everything with care in general - and I'm sure my bag would be taken good care of, probably better than I do LOL.