Claire hid nearby and secretly observed Otto and the Demon Flame Emperor. If she didn't know for a fact that this was their very first meeting, she might have thought they were old friends who had not seen each other for many years.
From the current situation, the relationship between Otto and the Demon Flame Emperor seemed to be pretty good, and the latter didn't show any signs of being protective of his food.
At least he didn't mind sharing some of the charcoal-grilled Dark Erosion Crab with Otto.
However, even when being generous, there were boundaries. When Welin tried to join in, the Demon Flame Emperor directly refused him.
If not for Konoheim holding Welin back, who knows what he would have done to the Demon Flame Emperor.