lightning to 3.5mm adapter

does there exist an adapter that allows you to plug your apple headphones with lightning connector into a headphone jack? If not, why? I ask this after having looked around and not found anything, only adapters for headphone jacks to be plugged into a lightning connector. I recently got some of these lighting connector headphones for my phone only to realize that I can't plug them into my computer, my iPad (at least through the headphone port), or the airline armrest to watch an in-flight movie. It seems that a small adapter I could carry around with me would fix this perfectly, but there doesn't seem to be any. Do I seriously need to carry around two pairs of headphones? I do have bluetooth headphones but I considered these headphones to be a backup, especially for traveling or when I didn't want to lose my charge too fast.