if it's not consensual, it's not play. learn the first rule of BDSM. "safe, sane, consensu...

Well, yes and no. Abusive relationships can still be classified as BDSM relationships, just not as healthy relationships. There are several layers to BDSM. There's the safe kind that, hopefully, all real people follow that involved things like safewords, communication, and limits. Then there's the darker, more extreme side. That's where you get into more abusive things, though even this side can be healthy if done right. That's the complex thing about BDSM, it's really easy to cross the line and become abusive. But even if your abusive, technically you are still in a BDSM relationship, just not a healthy one.