If you’re flying internationally, you’ll be required to fill out customs and immigration forms. Instead of hassling a flight attendant or a fellow passenger to use their pen, carry your own.
When flying into Hawaii, you will be required to fill out a Hawaii Agricultural Declaration Form. Passengers arriving with plants, seeds, and animals need to declare them. If you aren’t carrying them, you need to still fill out the form and indicate these items are not in your possession.
Ballpoint pens tend to leak due to airplane pressure. A simple fix is placing your pen in a plastic snack bag to protect your belongings.
Some airports are more technology advanced than others, you will find some airports will have a digital entry where you will not need a pen. In the meantime, just carry your own pen. Who knows you will need one to doodle on your cocktail napkin.