... You can try to bend over backwards to explain Vulcan marriage but its all right there in the episode...
From the episode:
But by the laws of our people, I could only divorce you by the kal-if-fee. There was also Stonn, who wanted very much to be my consort, and I wanted him. If your Captain were victor, he would not want me, and so I would have Stonn. If you were victor you would free me because I had dared to challenge, and again I would have Stonn. But if you did not free me, it would be the same. For you would be gone, and I would have your name and your property, and Stonn would still be there.
And doesn't Vorik bring up Vulcan mating rituals in the episode "Blood Fever"?
But at the end of the day, we will simply have to agree to disagree.
EDIT: They should do a Cheaters
episode where Spock is following T'Pring!