You held the flash beacon in your hand, looking up at the large fish-like man in front of you as he introduced himself. You now know him as Sebastian, and that the wares on his tail can be bought, aaaand the key card to the next room is on the table, free of charge.
You look at the code breacher, medkit, and the multiple sources of light on his long tail, but upon grabbing your desired item and holding it up to him to ask how much it is, your fingers accidentally press down on the button of your flash beacon, causing a sharp and sudden bright light to shoot through the previously warmly illuminated room.
Sebastian let's out a noise that's a mix between a growl and a groan, covering the anglerfish bulb and his eyes from the flash of light with a frown.
He throws out his upper left arm, pointing near the vent you came through. “GET OUT!!” He yells loudly, his right arm bent at the elbow and his hand clenched into a slight fist. . Looks like you pissed him off. Real bad, too. But he doesn't move to shove you out, nor does he say anything. He's still angry, no doubting that, but he doesn't force you out. He only glares.