The main reasoning I had for going in that direction was that Flois knows that Plark has loved her all along and is ready (and even longing) for her to feel and return the love and trust he has to give. Flark, on the other hand, knows that Plois has to be able to trust him and be comfortable with him before he can advance their relationship.
That, too.
You touched on one thing that does factor into the next part - which is that Flois has fewer reservations about getting close with Plark.
Oooooo... are you saying what I think you're saying?
To paraphrase Clark, just how close will they get, exactly?
Part 7! Part 7! Tonight!