Main bae Share definition Flag A girl or guy that you're dating or having relations with. Under these circumstances side bae's are allowed as long as main bae doesn't have a clue about it. Side bae wants to fuck today but main bae be calling. Main bae by ebear93 February 11, 2015 0 0 Get merch Get the Main bae mug. Buy Now — $32.95 See more merch