If this is really the case, you can report it in the discord channel of the game, telling how you did it. Maybe it's a bug. However, if you have used the console and cheats, this is the norm.
Viewing post in School Game / Sandbox, Simulator, RPG comments
I think there is some loop hole in game. Like if Ayano or yuki moves in your house, you can't have sex with other NPCs. Can't some possible alternative be added to have sex with them, even if Ayano or yuki stay at our place. Pretty good game, though my question is kinda, 😅. And it would be cooler if we could interact with yuki, Suzuki and Meiko through some other stories or content added to the game