I do love how some people expected a Harem route in this game. This game was not about getting them all in the end, there were very clearly lines about how each girl expected their time with you to go. Sharing is not an option for most of them, and the fact that you have basically been the town's biggest slut sleeping with every single girl means that you are probably going to have a playthrough where you end up alone.
I don't care if you "choose" a girl for your ending... if Katie for instance finds out you've been banging her mom and sister the whole time, that's not gonna be a happy ending for you. I hope you enjoy the inheritance because your ass is gonna be alone. You'll be lucky if she doesn't castrate you, stuff it and nail it on a mantle.
You get maybe 3 choices for a multi-girl route.
1. The most obvious is Debbie. Because Debbie has been the most obvious about it. She loves Lily. You are the only guy she has ever had feeling for, so she makes an exception for you. She also likes the idea of getting Katie involved.
But there are two other people involved in that idea. Katie is a jealous person who doesn't like when Debbie and Lily get too close to you, and Lily has just flat out stated that if you are with her, she's not sharing. So if that were to happen, the MC and Debbie would really have to work to talk them around into it. Even then, you have to explain to Katie that not only do you want a 4 way relationship, you've already fucked both of them. She's bound to take that well, right?
2. Jenna would be the second choice. But there is no way you are hooking up with Katie and Jenna together. It's not happening, no house harem for you. Both of them would be pissed at you. Monica would be pissed if you were screwing her and her daughters. That's not gonna happen. However, Jenna has very clearly had a girl-crush on Jolina for a while now. She also doesn't seem to mind if you have sex with her, so long as you love Jenna the most. So while she find the idea hot, she is still little shy insecure Jenna, and thinks that you will eventually leave her for Jolina. She may go along with the sharing idea, but it will be born out of that insecurity.
As for Jolina, I think we can all safely assume two things. One, she's bi. Two, she's most likely Bella's ex. The evidence is there if you look. But more than that, she has never once shown an interest in Jenna, and she was not remotely into the idea of Jenna watching you have sex with her. She was disgusted by it almost. Now whether that had to do with invasion of privacy or her not even wanting to consider ever having sex with multiple people, we can't know. But just like Jenna, Jolina is insecure. She does not like the idea that something could be going on with you and Jenna and she tries very desperately to make sure that's not the case when confronting you.
3. Wanda. Yeah, not what you were hoping for right? But it's true. She's probably the last and other best chance you have. Because she's a sub. She'll abide by your wishes and if you want to bring someone else into the relationship, she'll do so as long as she feels that you actually care about her past the roleplay of it all. Angel might go along with it for a bit. She might think it fun to keep Wanda around like a sex pet. But eventually, it'd split. You'd have to choose.
What about Zarah you may ask? Zarah is not interested in a full time thing with you. If anything, I think she probably has more of an interest in Monica.