If I do gheebah of a believer is it obligatory for me to tell them about it and ask them to forgive me? Is it true that Allah will not forgive me for doing gheebah of a believer unless that believer forgives me first? What if telling that believer (that I did his gheebah) will make him feel bad and damage my relationship with him, should I still tell him about it? If not, then how can I get forgiveness for that gheebah?