Daniel Gibson & Keyshia Cole -- The Family That Flies Together ... Is Back Together?

TMZ Sports now brings you concrete-ish evidence that the on-again/off-again marriage of former NBA star Daniel "Booby" Gibson and his R&B star wife Keyshia Cole is currently ON AS HELL.

We got video of the couple -- plus their adorable son -- out at LAX together yesterday and when we asked Booby how the relationship was doing he replied, "We're doing great."

The two were famously on bad terms until just recently ... when they were seen all over each other at the premiere of Keyshia's new reality show -- begging the question ... reconciliation?!