This isn't a kink for many reasons but at a basic level these people cannot seperate raw irrational desire/axiomatic beliefs from rational thought and ethics, thus these people cannot establish a bubble of consent to engage in kinks within.
No, these people are the farthest thing possible from someone with a kink who has a mature relationship around it (see as positive examples most bdsm communities and how sophisticated and nuanced their discussions are around agency and how to ensure it for others).
I know you probably agree with the spirit of this and I am not trying to nitpick you here, I just think it is important to reiterate what "kink" means, continously reclaim the word and not fall into patterns where we confuse two VERY different things.
These people are awful people, they do not deserve the title of "kink couple" lol.