If you watch the Night Changes performance posted on 1D's vevo account, you can tell Harry glanced at Taylor a few times (you can see where she's standing at the end of the video). When he started singing the chorus he looked at her quickly, for like a millisecond then looked into the distance. You can also tell how nervous he was since he had to put his hands on his mic to calm his nerves because he was shaking. He also looked in that direction a few more times. I'm so obsessed hahaha idc.