One of these things is the contrast between people's assumptions about the lifestyle, what it's actually like and the vanilla world appearance.
Often people assume its all kink, its not, it's a connection with someone in a way that's quite rare, deep and honest.
Because it's not all fettish land kink all the time, the lifestyles appearance in vanilla land can be quite a contrast to what people expect it to be. Often looking like a couple who are friends because they have a deep connection yet quite reserved, because they are waiting until later. Even old fashioned at times as the door is held open or he decides what to order for food that evening.
It's often the most 'accepting' that can have the most stereotypical assumptions of kink and bdsm, wanting to be 'supportive' to well.... get off or gossip off juicy info.
For some that stereotype is a kink for them, each to their own but RACK and SSC always. For me i like the exact opposite, i like the head fuck that goes with it because people like simplicity and when complex turns up, it can make their heads turn ;). Especially when you point out kink and bdsm, although fun together don't have to be mutually exclusive.
I quite like that contrast between vanilla and bdsm, i like how the stereotype doesn't hold up. I like looking at my partner knowing no one would have a clue by looking at us at the fun we can get up to. But i tend not to like assumptions in general, i very rarely live up to stereotypes, like many of us. Although pencil skirts are awesome.
It's the difference between 50 shades and secretary.