That's great actually! Because that's how you tell a story is different from the rest. In any other manhwa, their behaviour would be suggestive of second couple in making but not here. It is to show closeness and betrayal it seems?
I also don't know how to explain it but the author has done a good job in the story and characters. They don't seem generic. I don't know what to point out but there is something different about this story.
Thanks for letting me know btw!

I don't want lee saha and little brother as a second couple anymore.
There is no redemption for stuff like this. If he didn't spread the rumour, it is different thing but if he did, just no.
First of all little brother was a smol kid and he was about to ascend. Too much age gap for cute romance. Secondly, he is very evil. He purposely created a rumor that led to a village and other foxes as well suffering and dying. Not cute or anything that you can just brush over. And why did he do all that? Prolly because he was bored.
ML should have done worse things to him if anything and lil bro needs to stay away and act right! Acting cute doesn't work when you're a grown adult especially in front of your neighborhood murderer