laugh up (one's) sleeve

To try to hide that one is laughing at someone else. Ron may seem like a nice guy, but he laughs up his sleeve whenever he's around someone he dislikes. The popular kids laugh up their sleeves every time I walk by—it's so infuriating.

Common Names:

Name	Pronounced	Usage
Thaleia	-	Greek Mythology
Stanislava	stah-nee-SLAH-vah (Russian)	Czech, Slovak, Bulgarian, Serbian, Croatian, Slovene, Russian, Medieval Slavic
Macy	MAY-see	English
Emmie
Beard	[biəd]
Pyong-Ho	byung-ho	Korean