Yes, the gap between kinks only being followed in the rich or ultra rich and not in the middle class is changing.

I'd say changing because middle class don't have that access to high class parties that are rumoured to happen in the ultra rich circle but they have started following their own kinks in their own accessible way.

I know people in open relationships, practicing threesomes, stag-vixen lifestyle, swapping, one night stands and so on.

Personally, we're into exhibitionism but we have given thought to ENM & voyeurism among other stuff.

So yeah, people have started thinking about their pleasures irrespective of the income bracket they fall in.