so my girlfriend randomly goes to ask me something and then just says NEVERMIND instead of asking. then she says she cant ask me because its rude or something. so after being curious... naturally. i let it go. however. afterwards she began to act distance as she felt bad for making me curious and not telling me.
she doesnt wanna forget about it and since then shes been asking really distant.
imminent breakup?
should i beat her to it?

Sounds like a break up. Bring it up, ask her why she is being distant, if she refuses to tell you but is still acting distant then beat her to it.

fishy~
maybe u should ask her, in a relationship, communication is the main key, u cannot make a good relationship with a bad communication.