Micol--Alberto relationship (spoilers)
We are meant to believe that the relationship between Micol and Alberto has an overtly incestuous element, aren't we?
(Sorry if the answer to this question seems obvious in light of the scene of the two of them in the cabana.)
And this would help account for the problem Micol has developing romantic/sexual feelings for Giorgio--i.e., she's got a precedent in her life of an amorous attachment that is flawed and defective because it's with a brother figure?
(She tells Giorgio that romance/sex with him would be like "making love to a brother".)