Roast Queef Sandwhich is when saggy vagina lips enter the hole of the vagina during sex.They are folded inside by the penise of a male. The lips stay inside the females vagina while being heated or "roasted" until the sex is complete. She then runs and sits on the males face and proceeds to queef out the roasted lips into the mans mouth, which makes a roast queef sandwhich.
Chad:Steve bro! look at that slut walking towards us!
Steve: I know man she's got some massive beef curtains showing!