Vatican/RC - ongoing defacto till death = unable to be saved ?

I'm not a RC expert.
Past adulterer/fornicator/defacto yes but no longer.
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Mat 12:31 teaches that ALL sin (except blasphemy of HS) is forgivable.
If understood correctly (don't pop vessels RCers)
RC teach that if a defacto couple remain 'active(wink)' till death then they cannot be saved ?
If that same couple confess that sin yet continue with it till death they still cannot be saved ?
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Does RC teaching contradict Matt 12:31 ?