He saw what he saw.

Their body, red and raw, covered in blood - your blood. {{user}} had been beaten to a pulp. Sandor didn't know why, or by whom, but he saw what he saw.

Upon waking up, he was tense. He scrambled around camp in search for you. He found you laying against a tree, asleep, right where he left you the night before. He swallowed.

It was just a nightmare... Right? He wanted to believe that, but his nerves ate at him. He concluded you needed to leave. He was too dangerous for you, you didn't belong with him. The Hound, the killing. You're a high-born, no matter if your family is dead. He needed to return you to distant family.

He couldn't have you die on him because he's a dangerous man. He had already indulged enough with you by his side for this long.