First of all, just want to say that the Amber/Parker scene was one of the best I've ever played through in an AVN and I have played a lot of AVNs. I'm a huge fan of incest games, particularly where the relationships feel meaningful and romantic, and I feel this scene nailed those vibes.
Up until now I've played Amber primarily lesbian. She hasn't touched or been near any dicks with the exception of Parker. I've even had her avoid everything with Brody. This scene with Parker is, honestly, the first one I've experienced on my playthrough that actually feels like it meant something to her. Even scenes with Chloe have just felt like she's having some casual non-serious fun with her and the fact that Amber specifically said she wanted their (hers and Parker's) first time to be "special" made this feel very different to what she's been doing with anyone else up until this point, as well as the fact she referred to this as "making love". Personally, I'd like to see this change Amber a little bit. Like, if you've done this scene then her attitude and feelings towards the other people she's doing things with changes a bit because she thinks of Parker and her strong feelings for him as they have become much deeper, maybe even to the point where she'd consider leaving Brody. But I realise that this isn't that sort of game and we're probably more likely to see Parker simply getting brought in more when Amber's with other characters, but I can still dream of a sweet, happy ending with Amber & Parker, and perhaps some other girls thrown in for extra fun.
Speaking of which, I'd really love to see some action with Parker and Chloe and also both with Amber at the same time, of course. But me being me, I'd really like to see some nice build-up to Parker and Chloe, something that similarly feels meaningful and even romantic like it did with Amber and Parker. Although I didn't play it though it the whole way because it wasn't my thing, I started the Amber/Brody/Chloe scene, and aside from it not being my thing, it just felt really off that there would be this kind of sexual interaction without any build-up beforehand. Or maybe there was and I' not aware since I would have avoided that sort of stuff before, but even so, having not done anything before, it's weird that Brody would be OK with this even though I've had Amber avoid him the whole time. I wouldn't personally like to see something like that with Parker and Chloe, even though I have been following their paths and they would seem more open to it, because I think it would nice to see them build towards it rather than just do it randomly on a whim and have it feel like it means nothing.
My ideal scenario would be if Chapter 9 opens with Amber in bed still thinking about what she and Parker did, and because she can't get it out of her mind she goes to his room to have sex again and he's also still awake thinking about it. Chloe would walk by and see them having sex and would make eye contact with Amber as she's masturbating while watching them. Then in the morning, Amber talks to her about it and asks if she'd be interested in being with Parker, to which she says 'yes', and Amber essentially acts like a matchmaker, setting up situations for them to be alone and gradually start doing things with each other until eventually they go all the way, maybe even after they too have a special date and I wouldn't mind that being a scene away from Amber where Parker becomes the temp MC in it. Then after they've crossed that final line, we can start having Amber/Parker/Chloe threesomes. That would be sweet.