Associated Names:
Entretenimiento Sexy
Sexy Entertainment
섹터테인먼트

Summary:
Na Ga-in is the manager of a rookie girl group. One day, after clearing all the stages of an adult idol game, the girl group members he's in charge of become characters in the game he completed...? A status message appears before his eyes, blending reality and the game. [You need to have sex with the members in order to get the rewards!]

https://omegascans.org/series/sextertainment

I recommend reading the manhwa on PC using Yomikiru, and on Android using TachiyomiSY.