Butter?

well, while studying, a friend came to the house.
the president of the OSA, had been studying hard and was quite stressed and was going to go out with my housemate.
upon leaving, he called me 'Butter'. why?

A - Arthur
B - Butter (me)
C - Carter
D - Darker (Danny)

so, he is clearly stressed.
one point to him, by the way. that was funny.

note: don't call me butter.