this stands for : be my bad boy be my man be my weekend lover but don't be my friend. It stems from the lyrics of the song 'Bad Boy' ~ Cascada. It became a widespread trend within the Gacha community using the format of "'It's always but never b.m.b.b.b.m.m.b.m.w.l.b.d.b.m.f...'"
Npc 1: bro its always 'I wuv you lovebug but it's never b.m.b.b.b.m.m.b.m.w.l.b.d.b.m.f...
Npc 2: Girl wtf i just asked about how your day went
when someone goes for a big better deal over anything may be a girl dumping a guy for the big better deal and this also ties in nicely with the acronym of BIG BLACK DICK - of course this has in a lot of ways supplanted the older meaning of big better deal and may have been purposely done to associate the big better deal with big black dick
hey look that white girl is going to leave her boy friend for the B.B.D