It's when Kotetsu is practically folded in half in the bathtub, Barnaby fucking him hard and pressing his legs ever higher as he goes, water dripping everywhere, that it gets noticed. Barnaby's thrusts waver for a second, the water in the tub sloshing out onto the floor as their rhythm is interrupted, and he puts a hand to Kotetsu's foot. "Is this a mole?"
Kotetsu bends his leg a little, trying to avoid getting a cramp, and nods, his hips rolling to try to encourage Barnaby to return to the pace he had a moment before. "Yeah."
"It's... cute." Barnaby's hips have found a rhythm again and Kotetsu groans because it's slower than before.
"It just looks like a dark freckle." Kotetsu tries to slide back down the tiled wall so he can do a little more of the work and remind Barnaby of how much he had been complaining that he needed this only minutes before.
Barnaby pulls Kotetsu's foot up to his mouth and kisses the dark brown spot almost nestled between his toes. "I like it."
Kotetsu rolls his eyes. "Could you just get back to what you were doing?"
"You letch." Barnaby grins, though, and kisses Kotetsu's foot again before bringing it up to drape over his own shoulder as he grips Kotetsu's hips just under the water. A moment later, they're both focused again on that need and the sloshing water and the mole on Kotetsu's foot and the fact that the phone is ringing somewhere in the background don't factor in at all.