I feel the same, that was pure villainess to take it out on him while he's listening to her and fragile. I'm not saying fall for him but girl that was throwing away a playing card too lol
But ig the past Ariadne also treated him with the same care because he was her fiancé and she thought him his family because of his "false" affection (Unlike the present Ariadne, who is aware of her past and acts accordingly) but for Cesare never acknowledged that and always wanted something which was not his and once he get that he loses interest. That's why in present he wants Ariadne so much.
(Nonetheless it's just my assumption and I haven't read the novel so idk their past story)
Cesare def deserved all those hurtful words Ariadne said to him, considering what he’s done to her in their past lives. But damn, lowkey felt bad on that scene ngl. Saying that his very existence is what’s “wrong” is rubbing salt on wounds. Cesare, being the bastard son, never received familial love. He was cast aside for being the “other” son. Let’s be honest, Cesare turned out the way he is because of how his own parents treated him. Ariadne, however, in this current life time, is his breath of air. The only to ever treat him like a person … Don’t get me wrong, hate the dude, but damn that was some painful ahh shit esp since it was coming from someone he admired and liked. Tbh, that was foul of her.