Hate Me, but Let Me Stay Vol. 5 by Hijiki

Naoto and Hazuki's family continues to grow with the birth of their second son, Aoi! But not everyone is happy about the new baby in the house. No longer the centre of attention, a jealous Minato struggles to adjust to his new role as big brother, causing all sorts of headaches for his parents. Later, Shizuku departs for an overnight school camping trip, where things get tense when her omega friend Daiki is bullied by their classmates. Determined to protect Daiki, Shizuku takes a stand!
Binding: Paperback / softback