There are some unwritten rules on how best friends are supposed to act in facebook.

If you see a post by your best friend, you have to be the first one to Like it. Being the first one to like gives you a special place in the person's heart.

If you are browsing facebook and see that some of your friends postings or pics don't have any Likes, you have to Like them immediately.

You have to Like all of your best friends postings.

You have to like all photos and comments liked by your best friend.

You have to be the first one to wish Happy Birthday in their wall.