First off, I'd like to have a civil, technical discussion about whether the "netorare" tag applies to this game, and speculating about what I seem to want or what shitty games I allegedly like or don't isn't constructive. OK?
So back to the topic, I agree with most of your account of the scene. In particular:
I mean it seems that you agree that the scene is designed to cause jealousy. Or "test" for it, which just means that it will create jealously in some but not others.
I think the problem here is that people think that "cuck" and "netorare" are the same thing, and they aren't. Cuck is about the character, netorare is about the author's intent in writing the scene. This is NOT a cuckolding scene. She is not your gf. That's clear.
But it's still a netorare scene, because the dev wrote it to for the purpose of causing jealous feelings. If you're testing for someone's anger, you have to try to make them angry. If you're testing for jealous feelings, you have to try to make them jealous.
It's netorare. *drops mic*