When Cloud moves to push at his coat, Sephiroth pauses in what he's doing in order to sit back, lowering his arms to make it easier for the heavy coat to slide off his shoulders. Once it's off, he's bared to the waist except for the belts strapped around his chest. What the actual point of that particular harness actually is...is hard to say. Maybe there isn't one.

Once he's given Cloud what he wanted, he shifts closer - perhaps recognizing Cloud is looking for that closeness, or might want to touch him - before going right back to what he was doing, getting Cloud's belt unbuckled. Then he reaches for his pants, eyes flicking up to Cloud's face. "May I?"