I'm going to be honest, I don't think that Kiara and Reine should collab anymore. Reine has clearly chosen the path of males, and Kiara wants none of that. Rather than having them force a compromise, I think they should just decide to have nothing to do with each other. That way Reine can't taint Kiara when she's clearly chosen to remain male free.
The only other recourse would be for Reine to swear off male collabs forever, otherwise I think she should leave Kiara alone and out of the male collab bullshit. If she doesn't want to be an idol, that's her choice, but leave Kiara alone.