I headcanon that troll horns aren’t /that/ kind of sensitive to touch, but they don’t like people touching them because it’s more of a quadrant or otherwise intimate/close thing they do. I say this because if you grab something’s horns you can move their head, since horns are bones coming off their skulls. So Kismessises hold eachother still by the horns, or Matesprits pull eachother into kisses by the horns, Auspices hold the other two in their quadrant away from eachother,(1/2)
(2/2) and Morails knock horns or something after a feelings jam or something.
(3/2 horns I forgot) and otherwise friends just bonk your horns or use them to mess you up on whatever
I’ve always personally seen them as sensitive, in the sense animal ears are sensitive, so like if you scratch or rub the red base the Troll in question will just melt, with orange and yellow being less sensitive.