As servant I do not act solely on my own preferences, of course... But our host did not exactly make clear his identity on the invitation. [Although it's true nothing stopped Sebastian from turning in the doorway. Nothing except outward appearances and saltiness.]
But you see, he has been so insistent with me about his abilities to throw a party people here will enjoy. [After the stripper thing. See? Lucifer and Sebastian talk, apparently. If by talk you mean take turns insulting each other.]
I could not give an accurate verdict had I walked out the door immediately.