Season 1:

A young couple is shown kissing. They then have sex - scene is not explicit but the woman's breasts can partially be seen.

Einstein is shown to have romantic relations/affairs in both of his marriages.

Throughout the season Einstein is depicted as a womaniser as such (even in his elder age), not abiding by 'monogamy'.

Season 2 Episode two:

Prostitutes are displayed in a few scenes - some accosting men.

Mention of 'whore houses'.

Implied sexual activity - nothing is shown.