Goody-goody (Adjective)

Affectedly or smugly good or self-righteous.

All adjective clusters.

She was a goody-goody who always made sure to follow every rule and regulation to the letter, just to prove her moral superiority.
His goody-goody attitude towards his diet and exercise routine was starting to get on everyone's nerves.
The goody-goody politician's constant references to his own charitable work made him come across as insincere.
As a child, she was always the goody-goody one in the class, never speaking out of turn and always raising her hand to answer questions.
The goody-goody tone of the self-help book was so annoying that I couldn't even finish reading it.