Once Upon a Door Lock
Before Sasuke betrayed Konoha, before Kurenai fell in love with Asuma, and before Naruto attempted to sneak a peak at Kakashi's sick Make-Out Paradise novels; Neji, Tenten, and Lee had finally (and somewhat unfortunately) become a team. At first, the three seemed to abhor each other, Neji and Tenten teaming up on Lee and what not. But over time, things changed between them, and they had very strongly become the best of friends.
At the Hyuuga Compound, everyone knew Lee and Tenten as if they were family. The two would stop by to pick up Neji for a mission, to train, or just to say "hey". In the beginning, Lee and Tenten would nervously knock on the door and snap into a terrified bow when Hiashi opened the front gate. But after the residents of the compound got used to the pair stopping by almost everyday, Lee and Tenten realized that there was no need for formalities. Just jump the fence and be on their way.
Neji's family knew Tenten and Lee as his best (and probably only) friends, and grew comfortable with them roaming the halls. That's what friends do, right? ..Well friends until...
They found out what Neji and Tenten were doing behind his closed door. Hinata's shriek of embarrassment could be heard down the halls, and she quickly forced a large amount of milk-eyed servants and her fuming younger sister out the door.
Ever since, Neji realized it would be good idea to probably use the lock on his door, because privacy can lead to some pretty amazing things.
