fit like a _____
glove
keep sth secret
keep sth under your hat
to have a secret plan or idea prepared
to have something up your sleeve
in your birthday _____
SUIT
pull one's _____ up
SOCKS
not wearing any clothes, naked
in one's birthday suit
Have something up your _____
SLEEVE
at the drop of a _____
hat
Get hot under the ____
COLLAR
don’t lose your temper, stay calm
Keep your shirt on!
Off the _____
cuff
to do something immediately
at the drop of a hat
Put your thinking ____ on
CAP