Board Thread:News and Announcements/@comment-6533159-20151015224111/@comment-26397825-20151018104003

Except Summer can't just be a one night stand, or Tiayang wouldn't have 'shut down' after her death, since she was also 'Mum of the Year' according to Yang. He had to have loved her at least a bit, and Yang confirms this - she was his second love.

It's far more likely that, if we do follow the one night stand theory, they had a 'one night stand' as you put it, which soon became more as time passed - until she wasn't just a one night stand girl, but the new love of his life. Which means she isn't a one night stand; their relationship was a accident that developed into something amazing to them, and the loss of Summer was something that evoked a response Taiyang wouldn't have gotten if they were just close friends because of one night way back when.