to post them online?
It appears you already know the answer to this question! Why would you post images which were given to you in confidence? It is likely an invasion of privacy. More importantly, why not do the right thing by this person for whom you once care for, and destroy the images?
Since there is no conceivable good or reasonable purpose in doing what you are considering, why would you run the risk of unpleasant and expensive interactions with law enforcement and a potential civil suit. This sounds like one of those situations where later you cannot answer the fundamental question of daily life: What were you thinking?
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