Song Ci's thoughts weren't driven by a desire for martial techniques at the expense of her aunt. She genuinely wanted Ye Fei and Song Xuan to be together.
After learning the casual martial technique Ye Fei had given her, she increasingly realized how extraordinary her master was.
The Song family, despite its vast influence, could only come up with the trashy techniques that Song Renzong practiced. Yet, Ye Fei could casually produce something so powerful.
What did that imply? It wasn't hard to imagine that if her aunt were with a man like him, it would be an excellent choice.
As for Ye Fei's young age and his womanizing, Song Ci, coming from a prominent family, didn't see these as real issues.
