
I have a feeling the mother is secretly hostile towards him, or testing him. Maybe that’s why the younger brother looks so uncomfortable in this chapter,.... or the poor boys afraid of lightning

you might be right. Since the beginning of when they met she was messing with him. In mangas that I've read so far if a character is constantly messing with you like how the mother is, it turns out that it's just them trying to find out more about you but without it looking suspicious, there are other reasons, like you know the problems good looking people have to deal with.Those manga characters tend to be close friends, family members, parents etc.

The handkerchief was tied to a camellia flower, in the flower language the camellia represents the union between two lovers(pretty accurate since that’s kinda the first interaction they’ve had). The flower represents the woman, the leafy stem bit (that holds the flower together) represents the man who protects her.
Most flowers petals just fall off but the camellia falls as the whole flower, which is why it also represents eternal love or long-lasting devotion, even after death.
Hope you enjoyed this little bit of knowledge, I enjoy knowing what flowers mean
Dead they really sans-ed us, I ALMOST DIED WHEN I SAW THAT FUCKER IN THE EARRING