so, from Kuroto's remark, I assume the reason why Hotsuma sometimes bickering with Luka is because Luka can have a special place in Yuki's heart as his lover, meanwhile "Zweilt" only can as far as master and servant/family/friends relationship. well, I can understand though. Hotsuma share that bond with others, while Luka's bond with Yuki is special and shared with no one (づ￣ ³￣)づ
so, from Kuroto's remark, I assume the reason why Hotsuma sometimes bickering with Luka is because Luka can have a special place in Yuki's heart as his lover, meanwhile "Zweilt" only can as far as master and servant/family/friends relationship. well, I can understand though. Hotsuma share that bond with others, while Luka's bond with Yuki is special and shared with no one (づ￣ ³￣)づ