If it tastes sub-par you needn't lie for my sake Sherlock- I'll not be insulted, [he scolds somewhat easily, even if it is disappointing.

The demon seems to enter thought however, setting the thermos on the stone rail of the steps beside him, and bringing the hand back to his chin as he stares at the cup.] I suppose it oughtn't be surprising however, given how 'natural' blood drinkers have reacted to my methods...I wonder...

[And then, without any warning, he bites into his own wrist and holds it atop the glass as it bleeds.]

Just a moment, [he casually says, as if he were waiting for a soda dispenser.]