Speaking about your sin and flaunting it openly in front of your friends is prohibited in Islam and is a major sin. Exposing sins in Islam is one of the ways of spreading immorality among the Muslims, encouraging evil and tempting others to do similar things.

Jabir ibn Sulaym said: The Messenger of Allah said to me: “Beware of wearing one's lower garment below the ankles, because this is a kind of showing-off, and Allah does not love showing-off.”

Smoking is an evil and it is not permissible to indulge in it, or buy and sell it, or even to offer it to others.