As far as I am concerned what happens between two consenting adults is between them.
Some kinks give me the ick, but I'd never shame them. Sexuality is a complex thing and if something works for someone and it is between consenting adults, I don't see the problem. If someone's kink is not for you, just leave them to it. There's no need to go and shame them, you don't need to be involved with it.
The only time I see a problem is when one of the couple can't really give informed consent. If they are drunk / drugged, or if they haven't been given all the information to make an informed choice.
I've seen a lot of the intersectional feminazis suggesting a woman can never consent to BDSM with a man because the intrinsic power dynamics within society mean women can never truly give consent because they are oppressed. But I have this radical idea that women are grown-ups, and are equals to men, and their choices and autonomy should be respected. I find some of the insane woke stuff infantilizes women and tries to control them and prevent them from having the freedom of choice, which is utterly bizarre.
That said, we must be cognizant of innate power imbalances in relationships. Once you're aware of this and both recognise it then you can again achieve informed consent. Age gaps are a big thing to consider. As is coming from different socio-economic backgrounds. Education levels are another thing to consider. I'm not going to spoon-feed you intersectionality, though, if you want to learn more go forth and read. But also read with a critical mind, because there is a lot of insanity in post-modernist philosophically inspired literature.