QCTH

quietly chuckling to himself

similar to quietly chuckling to myself , lol , rofl or lmao

The situation or joke may be funny but doesn't want to LAUGH OUT LOUD

eg a prank

Johnny: Placing the bucket on the top of the door to prank his sister

Billy: hand over mouth

Door opens and bucket falls.. on his mother

Mum: WTF!!!

Johnny: Jaw dropped in shock

Billy: QCTH

qctm lol lmoa rofl roflmoa