Preference : The little things he does that you love
Bucky was the perfect man in your eyes, but there were always those details that seemed to stand out more than the rest.
It was the times when he seemed vulnerable. Whether he was confused with something, he was hurt or feeling weak, or a memory had come up that made him feel vulnerable. Those were the times that made him seem more human, and made you want to help him. That was also when you would fall more in love with him, because you were discovering more of his true self.
It was how Bucky always wanted to use his right hand around you. He always wanted to be able to truly feel you. He wanted to feel exactly your body, and not just a cold metal against your skin. He wanted you to feel like the two of you were close.
It was how much he cared. He always feared you being taken, or dying, or whatever the worst case scenario was. He always asked if you were the okay, or if you needed anything. Just anything to make sure you were happy and safe. Sometimes you didn't notice it, because he did it so much, but when you did, you feel more and more in love with him.
It was when he smiled at you. It didn't just show he was happy. It was that he was happy, he was alive, he was with you, and he was in love with you. While he did say "I love you" often, (which you loved as well) it was more in the gestures that showed his love.
He was your perfect man, but you couldn't help but love the little things he did.