For example,
HSDS - Zhang Wuji and Zhuo Zhiruo.
LOCH - Guo Jing and Hua Zhen.
ROCH - Yang Guo and Guo Fu.
SPW - Linghu Chong and Yue Lingshan.
Secrets of Linked Cities - Di Yun and Qi Fang.
Except for the Duke of Mount Deer - where Wei Xiaobao did marry Shuang-er (hopefully I got this character right).
Any other exceptions?
What could be some reasons for this phenomenon (non-marriage between childhood friends)?
1. Could it be the author's preference?