forbidden fruit

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