I don't rlly agree with you, he was more responsive when rosalia was in her female form, he did feel a certain tug towards Antonio but I think it's mainly from the pheromones. And abt the predatory comment, tbh I think he's just rlly clumsy and doesn't know how to express his feelings proprely.
I won't lie tho, he's a little weird
he decided he must like roselia after he saw antonio all wet after he saved him from drowning and then decided that since antonio was a man he must have been confused so he switched his affection to roselia, but i mean it is fiction so
imma say this over and over again. the grand duke is a gay man. he's attracted to the male antonio and not the female reoselia. plus he's a little predatory. i'm concerned.