Disclaimer: I don't own Naruto.
There's a barrier between Neji and his teammates, something that is small yet standing between them like a great divide.
Neji is sure that his teammates know about his parents. The "scandal" that the Hyuuga clan head's brother and a kunoichi had what amounted to a one-night stand and that he was the result isn't exactly secret. And what happened to Hyuuga Hizashi when Neji was a small child isn't a secret either; if they didn't hear about it when directly when it happened, then Lee and Tenten have probably heard about it through the grapevine at some point since.
But Neji hasn't got a clue about Lee and Tenten's parents.
They never talk about them; it never comes up in conversation. Lee and Tenten don't talk about their personal lives when they train; they exchange boisterous comments, encouragements, jokes and boasts, but never a word is spoken of their home lives.
And Neji can not ask.
There is an unspoken rule among all genin cells, whenever they are brought together. If a teammate does not talk about the parents, one does not ask about the parents. It is a sign of respect for one's privacy, and an act of trust; once a teammate trusts their teammates enough, it's presumed that the tales that lie behind the absence of information will be told.
Neji can not ask about the parents, so he is left unknowing, to speculation and guesses.
He doesn't know why Lee and Tenten seem to have no conception of family, why they are so surprised when Gai offers his home to them after they are brought together as a squad.
Neji doesn't know why Tenten does everything she can not to attract their sensei's attention at first, even though she trains just as hard as her teammates, if not harder. He doesn't know why she doesn't light up at praise even after she becomes comfortable hearing it the way Lee and other genin do.
Neji doesn't know why, in stark contrast, Lee is so desperate for Gai-sensei's praise, or why Lee becomes so devastatingly upset when Gai is, either genuinely or not, disappointed in him.
Neji isn't sure why Lee's bright eyes become so dull when Gai talks of bonding, why his dancing eyes suddenly become lifeless. And he doesn't know why Tenten shudders.
And he's quite sure he doesn't want to know why Tenten noticeably flinches when Gai touches her, even if it's only to pat her on the shoulder after a long day of training. He also doesn't want to know why she's so uncomfortable around every grown man besides Gai and Iruka-sensei.
There are many things Neji doesn't know about his teammates, because they never speak of them. He doesn't know why Lee and Tenten's clothes are both so shabby, or where Tenten got the long, thin scar on her upper arm from, because she's had it since she started attending the academy. He doesn't know why they're both so ill-fed looking. And he doesn't why they refuse to speak of it.
There are so many things Neji will never know about the people he fights alongside of every day, because he can not ask, and they will not tell him.
And as disturbing as he finds it, he knows he has to accept it.
Because if a genin doesn't talk about the parents, you don't ask.