Oh boi. I've red too much yaoi. And the last panel top it on.ha ha ha.
What does that even mean? ┗( T﹏T )┛
So by 'milk brother' they probably are referring to the fact that, it was common for nobility to not breast feed their own children. Instead, their nannies would be the one breast feeding them; their milk mother. This guy is probably the son of Ranamun's nanny, meaning they have been around eachother their whole life.
Oh, okay! That’s what I thought, but then I read lots of yaoi, too, so my pervy mind also thought of BL stuff! (▰˘◡˘▰)
(≧∀≦) ehehehe i get what you mean
Milk brother