guilty indulgence

Translations
виноватое удовольствие
Eating chocolate cake every night is her guilty indulgence.
Ежедневное поедание шоколадного торта — её виноватое удовольствие.
Definitions
A guilty indulgence refers to a pleasure or enjoyment that one partakes in, despite feeling a sense of guilt or remorse about it. This often involves activities or habits that are considered excessive, unhealthy, or socially frowned upon, yet are still pursued for the enjoyment they bring.