I have always used the term 'pussy' with girlfriends, referring to the whole caboodle - the vagina vs vulva debate seems a bit academic in this context. I like this word as it is quite gentle, descriptive and sexy. Mind you the first time I use it I feel a bit apprehensive that it will not go down well as it feels a bit old fashioned porn. With my current long term gf we sometimes use other words flippantly like minge, fanny, vag. I've never really been clear how women refer to this area, but I have never met a girl who says 'my vulva'. Seems its much more limited and clearer for guys parts.