I found Jane Black while looking up Best Women's Erotica 2007 (she's also a contributor) and found this fabulous essay she wrote at Good Vibrations called "S/M in the Suburbs:"
S/M brings a level of closeness between us that is in an entirely different category. It's how I tell him that I am still completely his, and how he tells me that he still completely wants me. Playing out an S/M scene colors our relationship for days -- and sometimes weeks -- afterwards. The afterglow lasts much longer than it does with vanilla sex. We're more gentle with each other. We touch each other more. We laugh more. We're more patient with the kids.
Perhaps ironically, the more time I spend being a mother, the more I crave the release of an intense scene. I want to shrug off that part of me that's always on duty, watching over my children and protecting them, and put myself entirely in my lover's power. The fact is, being a mindless sex slave -- relinquishing all volition, abandoning conscious thought for awhile -- can be pretty therapeutic...
The emotional connection we establish through S/M is an essential component of our relationship. Only my husband can touch that part of me, only he knows it's even there. I'm wearing t-shirts with spit-up stains and I'm carting around a diaper bag and I'm a soccer mom in a minivan. But I'm also, every now and again, a slave. It's part of what makes our marriage work, and it's part of what makes our family work -- though with any luck, the kids will never know it.