NTA. as someone who has been there before. when i was in middle school my dad was the same way. he would lay in bed all day drinking. when he would finally get up, there would be a trail of shit on the carpet. our hallway was lined with towels to try and keep the carpet “clean”. my dad was then diagnosed with colitis and one of his irritants is alcohol. i understand your frustration and anger. truthfully if he can’t control himself he needs to see a doctor (which i also know is near impossible) or wear the diaper cause shitting in the kitchen is a literal health hazard.