intimate
homely
esoteric
à deux
privately
in petto
confidential
privy
private
private message
privateness
have a word in someone's ear
have a quiet word
close-tiled
in secret
confidant
snoop
inquiry agent
secret
head-to-head
tete-a-tete
nonprivate
eavesdropping
proprietary
eavesdropper
personal life
cabin
tête-à-tête
chamber
anon
Sam Spade
hoard
private dick
contractorization
personal space
severalty
powwow
keep one's counsel
confidable
knowing
privatopia
by-interest
under the rose
query
relator
autonomist
tete a tete
ownability
keep one's own counsel
anonymity