I just can't help but think about when I see this gif, if reader was a tough tomboy girl, and a part of the bakusquad, she would follow these three around, while also not knowing that bakugou has a big fat crush on her,
And in this moment when she's standing on Kat's left side and the floor starts shaking and she doesn't make a scared move to clutch onto him but sparky did instead, it makes him all the more mad.