The koon-ut-kal-if-fee was a Vulcan mating ritual which literally means "marriage or challenge" and is fundamentally a wedding ceremony. Kal-if-fee was a "passion fight" in which a Vulcan challenges another over a mate. During the 23rd century, the fights were over when one was killed. The conflict was generally initiated when either two adult males wished to mate with one female during the pon farr, or when the female did not want the male that was arranged for her at childhood. The female could choose any defender she wanted, including herself or an alien. (TOS: "Amok Time"; VOY: "Blood Fever")
It was suspected that both challengers thereby broke their blood fever, assuming one of them was not killed first. (VOY: "Blood Fever")