there's no point crying over spilt milk
unavertable
ungrievable
you can't unring a bell
indispensable
uninfringeable
inconcussible
undismayable
unforgoable
untrickable
unquashable
undissuadable
shunless
unforsaking
undisappointable
insoluble
spilt milk
unappeasably
waste not, want not
unnegatable
unslakable
unerasable
unmourned
inerasable
unlamented
unscrewable
unmisunderstandable
undetesting
unmitigably
unrepulsable
unshirkable
irrecusable
unspoilably
nonsadistic
undeterrable
unsadistic
undespising
unsentimentalizing
untroublable
unmessupable
unslakeable
unbesmirchable
undeludable
undeletable
undiscourageable
uncontemptible
nontyrannical
unforestallable
untyrannical
nondisenfranchised