the opposite of just the tip. this is what you say when your girlfriend/wife/one-night stand thinks that "just the tip" is unclassy, rude, or chauvinist. If she declines your offer of "just the tip" with a disapproving scowl, you then proceed to ask her, "how about just the shaft?" In order to carry out just the shaft, you must pull a u-turn.
I told dat bitch I would do just the tip - and she said "hell no, you pig!" So, I said alright baby, how about I pull a u-turn and we do just the shaft?