So the group (basically everyone) was at Camp Half-Blood, and for one reason or another, Percy and Jason were left alone.

When everyone got back, they saw Percy and Jason, slow-dancing by the bonfire while talking to each other casually about how their opinions of colours.

Percy: "Blue is the best, obviously."

He commented, his hand holding Jason's. Jason only chuckled.

Jason: "Fair, but I kind of like yellow."

Jason added, holding onto Percy's waist. They either didn't notice or didn't care about their audience.