boast

Assalamoalikum,there's this matter that i am a bit confused about.There's this hadith of the prophet SAWS that states that all the sins of the believers will be forgiven except those who boast about them or disclose them. I dont remember it exactly but this is the main idea.I was wondering that there are so many muslims who conduct so many sins in public e.g. not wearing the hijab,singing,dancing etc.sometimes laugh along with people who are involved in sin like i dont mean they are mocking islam but maybe in enjoyment or whatever so does this mean that they will be in hell forever?I checked out one site that was pretty authentic and it said that according to the scholars understanding anyone who boasts of his sins will be in hell forever but on your site i found the answer to the same thing that only disbelievers will be in hell forever according to the scholars understanding. Can you explain to me please in detail this matter.May Allah bless you all.