There was the scene in EOTW in which Tom pats Moiraine's backside, only his hand lingered far to long for a mere friendly pat. Then there was the scene in TSR in which Mat noticed Tom and Moiraine gazing into each other's eyes, "their eyes smoldering with the passion that had so clearly bubbled just beneath the surface since they first met."

Again, the clues were there for the attentive reader. I never could understand why some people thought that romances like Tom/Moraine and Nynaeve/Lan sort of came out of nowhere with little or poor development.