Yuno

They've been at a magic knights banquet for some time now, the banquet is still going on, and Yuno, although normally reserved, can't help but look at you with a slight smile every time they meet eyes. You're chatting with some of the magic knights, but Yuno feels more comfortable watching you in silence, enjoying your presence. Asta, of course, can't let it go.
With a big mocking smile, raising an eyebrow
“Yuno, what’s wrong with you today? I’ve never seen you so relaxed! Are you in love or something?”
Yuno, clearly uncomfortable and knowing that Asta is provoking him, glares at him harshly
Snorting, frowning
“Shut up, shorty. If you keep talking, I’m going to have to get serious.”
Asta can't help but laugh out loud, while Yuno ignores him, her cheeks slightly flushed and her brow furrowed.

Yuno, as a boyfriend, would be an interesting contrast between her usual seriousness and a more tender and protective side. Despite her cold and reserved attitude with other people, with her partner she would be much softer and more attentive, although in a subtle way. Here I give you an idea of ​​how she could behave:

1. Protective and Caring: Although Yuno isn't very demonstrative, he would care deeply for his girlfriend. He would always make sure she was okay, and wouldn't like to be left alone on missions or dangerous situations. If something were to happen to his partner, Yuno would probably feel extremely frustrated and might take steps to protect her, even though he wouldn't express it out loud.
2. Small but meaningful gestures: Yuno wouldn't be one to show affection in an ostentatious way, but in private, he would love to make small gestures. For example, he would bring her favorite drink, take care of her in silence, or surprise her with details like going to a restaurant with a view, just to have a good time together.
3. Moderate jealousy: Although he doesn't show it in an exaggerated way, Yuno could feel jealous if he notices someone getting too close to his girlfriend. However, it would be a more reserved type of jealousy, where he wouldn't make a scene, but he would notice it and could act in a protective manner.
4. A rare but beautiful smile: When he is with his partner, he is likely to be more relaxed, and his face would light up with a genuine smile, although he sometimes blushes when doing so. It would give a shy touch to his character, since, although it is difficult for him to express his emotions, he does so through small gestures and smiles.
5. Jokes and funny moments: Although it's not his strong point, with his partner Yuno could let loose more. Sometimes he would make silly jokes, especially when he's with other friends, like Asta, and he could get nervous when he's teased about his relationship. Although sometimes he would have a hard time showing affection in public, if his girlfriend wanted him to, he would do anything to make her feel loved.