An interesting request, @zouex
They were probably fighting over Joxter having a lack of a work ethic or Moomin having a problem not even trying to get along with anyone but Hodgkins, either way Muddler does not like fighting and gets all self-blamey about it until he breaks down. Joxter tries to calm his boyfriend down, Moomin doesn't really care much about the sensitive ratdog tho.