Applying lipstick falls under the category of personal grooming. Personal grooming is not appropriate in public places.
I am frequently asked if a lady should apply lipstick at the table after a meal. This is probably the most violated or at least the most visually broken rule of grooming. If you must freshen your lipstick, excuse yourself to do so in private or in the restroom.
For all the men out there who think this doesn’t apply to them, this includes your application of lip balm. Do it in private.