With all due respect, Scarlett is a slut, so I don't know what reason my MC could have for wanting to be with her. In my opinion the further away from her the better. And her daughter Evelyn is another slut, so I'm not going to touch her even with a stick. So I personally think an option to tell them you don't want anything to do with them would be nice.
Regarding Bella, there are three options: Start a relationship with her and continue with Derek and sometimes the three of them have scenes together, start a relationship with her and continue with Derek but without Derek participating in the scenes with MC and Bella. , or not start a relationship at all. Of course, my MC isn't going to start a relationship with her while she's with Derek, so the first two aren't even options. What annoys me is that until you can reject her you have had several scenes with sexual content with her that you cannot avoid in any way.
Actually for a harem game, Scarlett and Evelyn are lousy characters, and Bella would only really be interesting if there was an option to make her break up with Derek. Honestly, as how they routes are developed, I think the best option is to pretend they don't even exist and don't even start their paths.