During the wedding season, some people have a habit that wherever a tent (mandap) is set up and food is being served, they sit down, eat, and walk away, even though they have neither been invited for the meal nor given permission. In this way, eating at someone's place without an invitation and without permission (explicitly or implicitly) is not permissible, and it is also against honor and self-respect. It is stated in a pure Hadith: "The person who goes to eat without an invitation, enters as a thief, and returns as a looter." (Mishkat al-Masabih: Pg/278, Hadith Number: 3222) (Book: Darsi wa Taalimi Aham Masail / Pg: 460)