Isn't it originally from a small sibling's charming mispronunciation of "brother"? My father and his sister were called "Bubby and Sissy" when they were little, which seems like the same kind of thing.
Anglo-Romani linguist Ian Hancock has suggested a link between “Bubba” and the Afro-diasporic Krio->Gullah word “bohboh” or “buhbuh”, “boy”: https://archive.ph/vead
(LW shows every sign of being the sort of person who would suffer a fit of the vapors over that line of linguistic connection, though.)
Although I suspect the LW would be equally shocked at the parents encouraging their children to refer to each other as "Brother" and "Sister" - I have heard that, but only in people from outside my region!
Addressing your siblings as “Brother” and “Sister” in China and Japan is proper grammar and etiquette, although the formality level can vary (and, moreover, birth order is built into the titles.)
It’s not typical in majority-white middle-class parts of the U.S. Midwest, but my best friend’s younger son routinely addressed her elder as “Brother.” (She’s half Chinese, and the household has been heavily immersed in various Asian media.)
no subject
Anglo-Romani linguist Ian Hancock has suggested a link between “Bubba” and the Afro-diasporic Krio->Gullah word “bohboh” or “buhbuh”, “boy”: https://archive.ph/vead
(LW shows every sign of being the sort of person who would suffer a fit of the vapors over that line of linguistic connection, though.)
Although I suspect the LW would be equally shocked at the parents encouraging their children to refer to each other as "Brother" and "Sister" - I have heard that, but only in people from outside my region!
Addressing your siblings as “Brother” and “Sister” in China and Japan is proper grammar and etiquette, although the formality level can vary (and, moreover, birth order is built into the titles.)
It’s not typical in majority-white middle-class parts of the U.S. Midwest, but my best friend’s younger son routinely addressed her elder as “Brother.” (She’s half Chinese, and the household has been heavily immersed in various Asian media.)