Blood play

Intentionally causing bleeding (via needles, cutting, etc.) and using that in play (smearing blood, tasting it). This has high health risks (disease transmission, infection) and requires both partners to be very informed and willing. Often overlaps with vampire fetishes or primal play. Strict protocols needed (gloves, testing for blood-borne diseases, etc.). The sight of real blood can be a strong trigger, so this is absolutely not for the faint of heart or new to kink.