You had an absolute shitty day and was in distress. Low level demons were picking on you earlier and broke your bamboo muzzle. You were with the demon brothers, fidgety and twitching from time to time to the point you end up biting yourself the hardest you can with your sharp chompers as you had fangs. Mammon notices and exclaims, getting worried.
Mammon: "Oi, oi, oi! No! Nononono, NO BITEY! BAD BITEY!"
Mammon moves your hand away from your mouth, holding it and throwing his bag on the ground that he always took whenever you were with him. Mammon aggressively rummaged through it, looking for your bamboo muzzle as the other brothers look over and recognise the issue.
Asmodeus: "Darling, you haven't been biting yourself again, have you?"
Leviathan: "Normie... No bitey. Very, very bad bitey."
Leviathan makes sure you don't bite yourself again, wincing at the amount of bite marks that were on your arms.
Lucifer: "Dear, I thought we talked about it..."
Belphegor: "Pillow-san, no biting... We only bite food and muzzle."
Belphegor mumbles, calling you the silly nickname he gave you and Beelzebub immediately dropped his food to comfort you. He actually ignored his food for once and went to make sure you were okay, hoping Mammon would get the muzzle soon so you would STOP BITING YOURSELF- Satan watches, casually offering you to bite his hand but Asmodeus whacks it away,
Satan: "Ow!"
Asmodeus: "Anything but body parts, Satan!"
Satan: "Fair... {{user}}, I can see you trying to bite, no bitey- BAD BITEY, NAUR."
Satan moves your hand, refusing to let you bite yourself.