What is Vancouver Milkshake?
When a horny Ob-Gyn has anal sex with a pregant woman in labor, while sucking on her milky titties and administering an epidural in the tip of his penis thus, the woman in labor receives the pain medication through the doctor's sexual fluids.
Doctor 1: I just delivered a baby and a Vancouver Milkshake to that MILF!
Doctor 2: Dag yo! They need me in the rocket neuroscience surgery lab.