Michael and Mae have sex. (Nothing critical is seen, but there are several close-up shots of their bare skin.) Their silhouettes are also seen when they get out of bed later. Christina removes her clothes (only her back is seen) and it is implied that she and Isaac have sex. They wake up in bed together the next day only covered by bedsheets.
People joke about sex (once in the presence of children). Someone makes a joke with sexual connotations about needing to know a man's age for legal purposes. Michael says dating a married woman isn't as bad as cheating.
A painting of a nude woman (only her back is seen) hangs in Mae's apartment.