It is very common for us all to use whatever charger that is plugged in to charge all the device with the same port but you might want to stop doing that with the Nexus 6P and Nexus 5X charger.
A YouTuber that goes by the name Nathan K posted a video on YouTube last month showing how dangerous it could be for users to use the Nexus 5X and Nexus 6P charger on the other devices.
According to Nathan, Nexus 5X charger will always deliver a full load of energy output no matter the device which means some device that might need less lead will receive more than it is supposed to which will eventually damage the device.
The same thing was also reported on the Google Nexus 6P charger. So it is best if you use the Nexus 5X and Nexus 6P charger for the smartphone only.