Consensual/non-consensual, cheating, interracial, affair and so much more

[beachy]

Currently I am craving for a plot that involves sexual lust, well planned plot, cheating, seduction, corruption, forbidden and so much more exciting kinks and ideas.

Some plots that could be considered below but also open more interesting ideas:
1) babysitter x married dad
2) step brother x step sister
3) girl x sister's boyfriend/husband
4) woman x husband/bf's best buddy/boss
5) best friends