Cheers. It was way way down. I'm gonna paste it here in case someone is looking for it:
Globally, you avoid Scene 7 by paying attention to Cassie and giving her some "pure love" vibe.
The first key choice is to talk to Cassie while in the lingerie shop, during Day 3. Avoid the "Ok. So what?" option.
The second key choice happens on Day 4 morning, when you meet Cassie in the living room : "Give her a proper kiss." / "I'm sorry." / "You keep saying that."
The third key choice happens on Day 4 either at Cassie's place or during the night, with Eve. At Cassie's place: "This morning was very difficult to handle." Or at night in Eve's bedroom: "I don’t accept it." Yes, that means that you can meet Kelly and still have the throuple path right.
The fourth key choice happens during Day 4 night when you join Cassie in her bedroom. Choose "Except maybe cuddling a bit and having a nice talk." Finally, during Day 5, in Cassie's bedroom, you should be able to choose the following options: "I will tell you everything", "I would choose no-one", "Apologize".
With more than 67 affection points for Eve, and Cassie, you will avoid Scene 7 and Cassie will stay home with you.