Narrated Abu Huraira:
I heard Allah`s Apostle saying, “all the sins of my followers will be forgiven except those of the Mujahirin (those who commit a sin openly or disclose their sins to the people).an example of such disclosure is that a person commits a sin at night and though Allah screens from the public, then he comes in the morning and says:”o so and so, i did such and such (evil) deed yesterday,” though he spent his night screened by his Lord (none knowing about his sin) and in the morning he removes Allah`s screen from himself.”
(sahih Bukhari).