Since we have no idea who the last blue and red paladins were before I bring you this headcanon.
Coran and Allura retelling about how the last blue and red paladins were in love and Keith and Lance just getting flustered and taking huge steps away from each other.
Coran lets slip that a recurring pattern with the paladins was that the red and blue paladins would always fall in love or end up in a relationship.
They both leave in opposite directions and no one talks about it until one night at dinner Pidge, seeing Lance watching Keith, nudges him.
“You can’t break tradition Lance that’s bad luck, ask him out already.”
Lance tries to convince everyone he’s fine as he’s choking on goo and struggling to breathe.