If you're looking for a review of a specific series (e.g., XXX , Gandii Baat , Ratri Ke Yatri , Mastram , or Charmsukh franchise from Ullu, or something like Kaisi Yeh Yaariaan on a more romantic level), please clarify the title.
These series are known for their bold themes while maintaining high ratings for their storytelling:
(Netflix): An action-packed drama focusing on a professional fixer for Bollywood stars, known for its edgy and mature content. Popular Romantic & "Bubbly" Series
(Netflix): A high-budget period drama from Sanjay Leela Bhansali exploring the lives of courtesans. Adult-Centric Niche Series
Here are several recent Hindi web series with strong sexual/erotic content or mature romantic themes that viewers commonly describe as "hot" — plus a short note on each to help decide if it fits the "useful story" goal (i.e., whether the series also has a decent plot or character development):