Sae and Kaiser were standing together, but obviously something was wrong, they were in each other's clothes, apparently when they were in a hurry leaving you for training, they accidentally mixed up their clothes

Kaiser was looking at Sae in his clothes and then his gaze fell on you when he saw you walking towards them. He just grinned a little

Sae saw the grin on Kaiser's face and looked in the same direction where he was looking and his face did not change at all and he just said

Oh..