What I find most interesting (and simultaneously horrifying) about Utena’s growing affection for Akio, is how we see Utena’s sense of morals versus her desires come into play, because it goes a step in giving Utena herself the complexity of character she’s still not very adept at, while testing her belief in the ideal of being a Prince.
Because Utena knows that attempting to enter into a relationship to a man engaged to be married is wrong. Sure, Wakaba eggs her on in her own way, but Utena has always lived by a sense of values that emphasizes that she not harm people. Yet those values come head to head with her own, human desires, which understandably troubles and confuses her, she feels bad for feeling the way she does. The situation is, of course, not helped one bit by Akio’s manipulations welcoming her into submitting to that desire and abandoning the morals she has.
But there is also something else, or someone rather: Anthy. I still think she doesn’t quite understand what it is yet, but there is something that Utena feels for Anthy, and this she is confused by as well, because she’s had a lock-on to her mysterious Prince for years now, no one else was supposed to enter into the equation. Yet here is Anthy, being something more than a friend, and slowly, something much more than the Rose Bride to be protected as well. And this conflicts Utena, I think, because these feelings are things she wants to explore, but due to what is happening with Akio, she doesn’t know what’s appropriate.
And that isn’t even getting to what’s implied that Anthy thinks about all this (though it will, soon).