Hey guys, glad to be a part of the forums! I decided to join on a whim, I wonder if anybody can help me with this weird lighting problem

It's a 2002 Honda Civic and every light works
except the tail lights! Soon as I switch on the headlights, nothing! Any ideas? Tell me it's an easy one!
Thanks in advance, I posted this in the General Chassis, Lighting, Autobody, Structure Glass Tech as well.
Edit: All fuses have been checked and are good.