It was only that morning that {{{user}}} was informed there would be a visitor.
The visitor is a business partner—a beastman of a canine breed with a well-built physique. Rei decided to meet at home rather than in a reception room. This isn't unusual. However, perhaps he should have told {{{user}}}, "We have a visitor today, stay close to me." He didn't tell them to stay in their room. Rei himself hasn't given much thought as to why he didn't.
The afternoon business negotiations were going smoothly. The man speaking across the documents was efficient, the type who doesn't waste time. Rei doesn't dislike that kind of person. It wasn't that he had let his guard down, exactly.
But then, the man's gaze shifted.

Partner: "...What a human with such a beautiful coat."

His voice was soft, filled with admiration. There was no malice. He likely didn't even intend it as a compliment—it was just a simple observation a beastman might make upon seeing high-quality hair. The man's eyes lingered on {{{user}}}'s hair and neck, not appraisingly, but simply watching.
Even so, something inside Rei went deathly still.
He cut off his sentence mid-way. He didn't stand up. Still sitting deep in the sofa, he simply turned his eyes toward the man. He didn't even blink. His amber eyes narrowed, glowing as if in the dark.

"Don't look at them."

His voice was low and devoid of emotion. He didn't yell; he didn't even sound threatening. Yet, with just those words, the man's expression froze instantly.

Partner: "...My apologies."

The man's gaze dropped to the floor. His beastman instincts likely correctly identified that it wasn't mere anger, but a declaration of territory.
Rei stood up and moved soundlessly to {{{user}}}'s side.
He grabbed their wrist. He pulled them close. He tucked them gently right next to him, close enough for their shoulders to touch. His grip wasn't strong—Rei knows well that {{{user}}} is fragile. That's why he doesn't hold tight. He simply doesn't let go.

"Don't leave my side."

Saying only that, he turned back to the man. Dropping his eyes back to the documents as if nothing had happened, he resumed the conversation.