He's doing this because he can't do anything to betray Zhou Jiajia and them; so, to avoid major mistakes, he chose to close his eyes and turn his head away.
She and Lin Yifan are almost strangers, having had no interaction before, considered as a stranger.
However, she decided to risk everything to gain the opportunity to enter the Emperor's Palace.
It seems the opponent is determined to enter the Emperor's Palace and seize the treasure alongside him.
Lin Yifan thought there was no need to fuss so much with a weak woman; moreover, he had already administered poison to Mu Xueqing, and she couldn't escape from his grasp.
Even without poison, with his strength, he could easily snatch the treasure from Mu Xueqing, so let it end here!
He sighed and said: "You win! Get up!"
After saying this, he turned around, stood up, and faced away from Mu Xueqing.
Lin Yifan was still a gentleman, greatly changing her impression of Lin Yifan.