There is a tall glass of water here, lightly covered in condensation. It is slightly cool to your touch. 

You feel so thirsty. 

You lift it to your lips and tip it back, eagerly, your tongue reaching out to capture that much needed first drop. 

You furrow your brow in confusion as it fails to come. As you draw back your head to get a better look, you see a thick viscous drop falling towards your tongue.