emotionless
He looked on emotionlessly as they argued with each other.
She thanked them quite emotionlessly for the help they had given her.
"The situation is very serious," the doctor explained emotionlessly.
She spoke quietly, emotionlessly, and in a controlled way.
He stared at me emotionlessly as I told him what had happened.

SMART Vocabulary: related words and phrases

Not showing or feeling emotions
anodyne
anti-sentimental
belie
bite
bite your lipidiom
glaze
hard-bitten
hardened
icily
impassive
poker face
reserved
reservedly
sphinx-like
stiff upper lip
unmoved
unprocessed
unresponsive
unresponsively
unresponsiveness