Where does “mặt búng ra sữa” come from?

mặt búng ra sữa (Vietnamese) comes from Vietnamese bụng, from Khmer បង, from French bon, from Middle French bon, from Old French bon, from Latin bonus, from Old Latin duenos, from Proto-Italic dwenos — to show favour, revere; to fail, to lag, to be...

Ancestry of “mặt búng ra sữa”, step by step

mặt búng ra sữa traces back through 3 separate lines of ancestry.

via Vietnamese bụng

StepLanguageWordMeaning
1Vietnamesebụngbelly; feelings, personality
2KhmerបងI, me, my; you, your; elder sibling
3Frenchbongood; right, correct; sexy, hot, smoking hot
4Middle Frenchbongood
5Old Frenchbongood
6Latinbonusgood, honest, brave, noble, kind, pleasant;...
7Old LatinduenosAlternative form of duonus
8Proto-Italicdwenosgood
9Proto-Indo-Europeandew-to show favour, revere; to fail, to lag, to be...

via Vietnamese

StepLanguageWordMeaning
1Vietnameseto check
2Latinrēxking, ruler
3Proto-Italicrēksking
4Proto-Indo-Europeanh₃rḗǵsking, ruler
5Proto-Indo-Europeanh₃reǵ-to straighten, to right oneself; right; just

via Vietnamese sữa

StepLanguageWordMeaning
1Vietnamesesữamilk
2Proto-Vieticp-rahmilk
Every word from Proto-Indo-European dew-