Dom/sub... I read a Reddit thread where a young person discovered that they enjoyed an activity during sex, that was completely innocent and not at all atypical, and now they're dom and their partner is sub. BDSM is trendy, I guess. That's no good. (Not that I'm looking down on BDSM, just that if it's trendy, they probably won't internalize BDSM consent culture or technical knowledge about safer practices.)

BDSMers also use Top/Bottom terms, rarely as their BDSM role, but sometimes. Top is the active, giving partner, bottom is the receptive partner. So you can have a "Rope Top," who likes to tie with rope, or a "Rope Bottom" who likes to be tied. Top/bottom is usually concordant with Dom/Sub, the common roles, but not always... they love to play with words to keep their role personas intact. Plenty of "Doms" like getting beaten, for instance. Switch would be vers.