à deux
intimate
homely
privately
close-tiled
in petto
have a word in someone's ear
have a quiet word
esoteric
private message
secret
privy
private
in secret
tête-à-tête
privateness
under the rose
proprietary
nonprivate
closet
prep school
powwow
preparatory school
personal life
hoard
in camera
home school
inquiry agent
interiority
inwardly
heart of hearts
offline
in confidence
seminary
inside
eavesdropping
private dick
head-to-head
tete-a-tete
snoop
behind closed doors
closeting
confidential
chamber
by-interest
sit in on
academy
heart-to-heart
knowing
auricular