This was requested by casifersangel
Castiel watched you as you got to work on setting up a Christmas tree. You put it together piece by piece and fluffed it out. The angel watched with a confused expression. "Why do you have a tree in the map room Y/N?" he asked.
"I'm decorating the bunker for Christmas," you told him.
"I don't think the boys have ever done that," he said.
"Well I'm here now," you said with a smile, "wanna help?". He nodded.
"How can I help?" he asked. Soon you had the angel helping carry some boxes of Christmas decorations you found in a storage room to the map room. Soon you were organizing the tree ornaments as Castiel started untangling lights. Once he was done you showed him how to wind them around the tree so they would look nice. Then you two got to work hanging the ornaments. The funniest part was when you put the angel on the tree. Castiel went on about how he had never known an angel to ever sit on top of a tree.
After the tree was done he helped wrap some lights and garland around the railings of the steps. You also hung stockings with names on them on each person's bedroom door. When that was done you and Castiel just set in the library as you admired your work. "It looks nice in here,". Castiel said.
"We're a good team Cas," you said watching the blinking lights on the tree.