MarkPhoenix:
SNM: Kira Nerys, from Star Trek: Deep Space Nine.
I have two others from the same series:
1. Worf and Jadzia Dax
2. Quark and Grilka (his Klingon ex-wife)
In both cases, the idea is the same -- with Klingons, foreplay and S&M are usually synonymous, so it wouldn't be too much of a stretch to think that both couples engaged in spanking at some point.
Of course, there are also Counselor Ezri Dax and Doctor Julian Bashir.
They don't seem like rough-and-tough types (although part of Jadzia is in Ezri, after all), but they both have professions (psychologist and physician respectively) that would allow them to 'prescribe' treatments for one another, some of which might result in medically-sanctioned spankings.
Also, they both have underlying guilt issues--Ezri RE 'abandoning' her family (by reluctantly accepting the Dax symbiant) and Julian RE having a normal, successful life although other genetically-engineered humans are kept in confinement.
They each might need a good ass-thrashing from the other on occasion to help deal with their respective guilty feelings, which are largely irrational but nonetheless quite real.
Keiko O'Brien might be a pretty strict disciplinarian, of Miles and/or Molly, and AFAIC it's very likely that Leyta paddles her husband Rom on occasion.
The Intendant, the mirror universe counterpart of Kira Nerys, she's highly sensual and could well be into lots of kinky sexual stuff, including corporal punishment... --C.K.