forbidden fruit
US /fɚˌbɪd.ən ˈfruːt/
UK /fɚˌbɪd.ən ˈfruːt/

1.
buah terlarang
something desired or pleasurable that is not allowed or is illicit
:
•
The secret affair was their forbidden fruit.
Perselingkuhan rahasia itu adalah buah terlarang mereka.
•
For some, staying up late feels like a kind of forbidden fruit.
Bagi sebagian orang, begadang terasa seperti semacam buah terlarang.