these quiet nights (слэш)

Merlin breaks off as his gaze falls on Arthur, and all the colour drains from his face so quickly, Arthur’s afraid he might just faint. The picture is only worsened by how still Merlin’s suddenly become, except for where his chest starts to rise and fall increasingly fast.
“Merlin?” Arthur asks, not bothering to mask the worry that’s curling around his ribs, and he takes a step closer, pain all but forgotten.