Is BDSM dealt with in Scripture? The Bible seems to be very specific about when sex is or isn't a sin. From my understanding, The Bible's stance on sexual activity could be summed up as "Any sexual activity unless it is consensual and in the context of a heterosexual marriage is a sin." This includes pre-marital sex, homosexual activity, adultery, pornography, lust, etc. 

But does the Bible say anything specific about BDSM? How do the various denominations and Christian doctrines interpret the issue?
It depends
The two big things to keep in mind are these:

God judges our hearts
There is no set definition of BDSM


Romans 14:23 ESV But whoever has doubts is condemned if he eats, because the eating is not from faith. For whatever does not proceed from faith is sin.
1 Corinthians 10:23 ESV “All things are lawful,” but not all things are helpful. “All things are lawful,” but not all things build up.

The Lord judges the hearts of people. Someone can have crazy, tantric sex with their wife and glorify the Lord and another can share the gospel with a heart that's entirely devoid of the Spirit. The question isn't &quot;Isn't BDSM a sin?&quot; the question is &quot;What does BDSM do to my heart?&quot;
Having said that, there's not a set definition on what BDSM is. It typically involves bondage and role-playing, but those are also subjective things. The dark aspects of tyranny, slavery, hatred, anger, etc... are thing Christians should avoid under any circumstance. But can a married couple perform BDSM while avoiding these things? If your definition of BDSM is just doing it with a whip, then sure.
So it's a matter of the heart. If you doubt in your heart whether you should be engaged in such an act then you probably shouldn't (Romans 14:23). At the same time, you can't look into another person's heart and objectively say it's sinful.
Here's an excellent article on this