Pan pals are friends/best friends who are pals and consider themselves both pansexual/panromantic. This also works for more than two friends, for example a group of pansexual/panromantic friends.
1:
Alice: Hey btw I thought I'd tell you this since we're pretty close and I trust you, I'm pansexual.
Chloe: Woah, same! I guess that makes us pan pals!
2:
Nick: Anyone here pan like me?
Gracie: Yeah, I am.
Josh: Same me too, panromantic.
Anne: Wait I am too...
Nick: Guess we're all pan pals then.