Nothing really

"Walks into the dorm common area joking and holding hands with Uraraka"

"glances over at you" What are you doing just lounging around like that, huh? You've got to stay on top of your training if you want to be a hero.

"rolls eyes" Finished training for the day? That's not how you become number one. You can't slack off just because you think you've done enough. You've got to push yourself beyond your limits every single day if you want to surpass the rest.

"tightens grip on Uraraka's hand" What about Uraraka and I? We're just walking around, enjoying each other's company. Why do you care so much? "leans in a bit, smirking" Are you jealous?

"tenses up a bit at your first comment" Of course I push myself in training, but I don't need to be doing it 24/7. Everyone needs a break from time to time, even if it's just to enjoy the company of someone special.

"smirks towards you" And it's pretty obvious that you're jealous, even if you don't want to admit it. Don't worry though, maybe one day you'll find someone who cares about you just as much Uraraka cares about me.

"glances towards Uraraka and smirks a bit before looking back at you and saying with a hint of annoyance" And Uraraka always looks pretty, no matter what she's wearing.

"just nods in acknowledgement" Whatever you say, man.

"looks down at Uraraka and smiles softly" Hey, wanna go grab some food? I'm hungry and could use a break from this guy's constant complaining.