Nagi doesn't notice at first, too busy trying to convince Isogu that he is far too large to climb up into his lap, because apparently his intent was to just sit there and wait for food to be deposited into his mouth like a giant dumpster.

"For Arceus's sake, would you-!"

Then he catches Neku's eye, briefly, noticing the look on his face...and it causes him to flush deeply, quickly looking aside while still pushing Isogu off of his lap with little success.