A little bit "C.H."
Like a pun, which is a play on words, "A Little Bit 'C.H.' " is a play on letters... If you were to spell 'bit' as B.I.T. and then add C.H. at the end of it, you get "B.I.T.C.H." This is a sly, somewhat silly way to call someone a little bitch. You can even explain it by doing that... "You know, a little bit 'c.h.'? ...A little "B.i.t.-- c.h.?"
Well, aren't you a little bit "C.H." today!