Why does she need to stay with him until his injury is recovered?
Any kind of 'Renaissance Route' feels out of place as well given everything that's happened. There have been like zero positive interactions between the two since maybe halfway through part 1. In fact things seem so highly contentious with the kidnapping etc. that it's hard to imagine any kind of rekindling of their relationship that wouldn't feel extremely forced. Will she be in some kind of mortal danger and he'll swoop in like captain save-a-hoe at the last second and she'll decide to keep him around so he can watch as she continues to screw everything else with a pulse and he suddenly discovers his cuckold nature? A true love story for our generation.
Because she feels that she owes him that much at least. Remember, although the player may hate Andrew as a character, Anna doesn't. She still does have some affection for him, even if she believes they no longer have a future. So she's not prepared to end their relationship, whilst she still believes he needs her to get back on his feet.
Originally, there wasn't going to be a Renaissance Route, and it still hasn't been officially confirmed. But Anna's choices for her future with Andrew, appear to confirm that such a route is going to happen. Basically, Awake, the other Dev, persuaded Deep to include a route where Andrew and Anna end up together. So regardless of whether you think it's right or not, that is what is going to happen ( probably).
Andrew and Anna may not be sexually compatible anymore, but despite everything Anna still retains feelings for him and Andrew is still completely in love with her. Whether Anna's remaining feelings are sufficient for them to make a go of it, is of course up to the players to decide? And it will be determined, by which choice you made, on Tuesday morning, whilst Anna was lying in bed.
If you made the top choice, Anna will leave Andrew, sometime in the future. Their relationship is already over, but Andrew just isn't aware of it yet.
If you made the bottom choice, then they will get back together. Anna will( eventually) take the cure for her condition automatically, causing her overactive sex drive to diminish significantly, and she'll start to realise that everything that has happened in this game, was heavily influenced by her aberrant sexual behaviour. Her need to cheat will no longer be a factor, and if she wants to, she'll be able to rebuild her relationship with Andrew.
The middle choice is the one that's a bit more debatable. She decides to remain with Andrew, but acknowledges that she still may need to have sex with other men, because Andrew can no longer satisfy her. That's probably going to lead to an open relationship, what I think might be a hotwife type of scenario? So I think there might be two renaissance routes for Andrew eventually?
I suspect that if you chose for Anna to split up with Andrew, all the future sex content with him, is going to be blacked out. Anna will just make up some excuse why she can't have sex with him. I also think, that with the top and bottom choices, Andrew will never find out, that Anna has been cheating on him.
For my main route, I originally chose for Anna to dump Andrew. But then when I began to suspect the middle choice might lead to a cuck scenario, well I changed my mind. Because if there's any male character in adult games that I want to cuck more, then it's definitely Andrew. So I am kind of hoping now, that it will lead to that. The only problem is, that I asked Deep about this several years ago, and he suggested it wouldn't happen. But he also claimed back then, that he had no plans for Anna to become a dominant character. And he's already backtracked on that to some extent, so who knows? Hopefully we'll get a route, that leads to something like that?