How long does the smell linger, and how can I make sure others can’t tell i’ve been drinking?

Usually I drink at night and the next morning i just eat some peanut butter and brush my teeth to make my breath smell okay (incase it smells) as well as showering. I see many posts here where people say even if you don’t smell it, other people def do, though i’ve been around people the morning after getting pretty damn drunk and no one seemed to notice. How can I tell for sure if other people can smell it?? Or what ways can people tell i’ve been drinking?