Responses

They are brothers, Leegang's mom has the exact same hair color as Gio but Gio gets most of his features from Leegang's dad, even the lovey-dovey part of Gio's personality. While it is also shown thay Leegang's mom has a photo of young Gio hugging a teddy bear and Leegang's grandma stating that she believes that her grandson is still alive when another woman was talking about some kind of death anniversary(not so sure about the translation in this part).
I'm sure Leegang isn't drunk at all and is going to see them kiss and "blackmail" them because he is just bored and doesn't kno how to function like a normal human being x)