dirty vlad is when you give oral sex to a girl who's menstruating and sucking her period blood, while she crushes your head with her thighs. this ends when she cums so much that the blood to cum ratio is over 50/50 or when you go unconcious due to lack of oxygen because of the thighs blocking your airways.
person 1: "damn, i still feel a metallic taste in my mouth after pulling off a dirty vlad last night"
person 2:"well at least you didn't stop go into cardiac arrest from lack of oxygen this time"