You have common interests
Best friends are people who have a lot of various things in common. They like the same kind of food. They are keen on the same genre of movies and listen to the same music. Common hobbies make people close friends because they have a lot of exciting topics to talk about. Travelling with your best friend is another advantage and if you are in a romantic relationship with your best friend, then you know that staying in the same room with the person won’t cause any issues and misunderstanding. Sightseeing tours, concerts, excursion and eating out do not annoy you.