Having a sister is fun, and life is ten times more fun when she also happens to be your best friend. Having someone growing up right next to you, under the same rules and expectations as you, is someone you have to stick with. This is a bond like no other, and these are the things that make this the best kind of friendship.

1. You have the same sense of humor.

Whether it's from growing up and hearing the same things from your parents or from being around each other all the time, you both find the same stuff funny. Along with that comes many inside jokes that only you two know. You know exactly the kind of stuff that will make her laugh because it makes you crack up too.

2. You can be weird around each other.

While sometimes you might feel like if you do or say a certain thing around your friends you'll get strange looks or might feel judged, you never feel this way around her. You know that she can be just as goofy around you, so you can always let your guard down around her. She's the one person you can act like an idiot around, and she won't care because she acts the same way too.

3. You can get in a fight, and be totally fine in five minutes.

Since you guys are so close, you know exactly how to get on each other's nerves. So when you do get in fights, it's a battle of who can get the last word in followed by a period of silence. Then you can't stay mad because she does something to make you laugh, no matter how hard you try to keep a straight face.

4. You can tell each other anything.

When you feel like you have no one to talk to who will understand, you know you can go to her and she will listen to all you have to say. She can get you through whatever you are dealing with and is always there for you when you don't want to tell any of your friends or anyone else.

5. Hanging out with her is just as fun as hanging with your friends.

In fact, being with her can be more fun than being with your friends. You guys have the signature places you go to and things you do with each other, whether it be your favorite restaurant or place to shop. Even if you're just hanging out at home watching a movie and doing nothing, you're perfectly content.

6. You can communicate without saying anything at all.

So many times you find yourself in situations where something weird or funny happens, and it would be inappropriate to say something about it out loud. You can glance over and see her staring back at you with a certain look, and you instantly know you both are on the same page about whatever is going on.

7. You have an extra wardrobe.

Whether you need to borrow clothes, shoes, or jewelry, you know exactly where to look. Both of your closets are interchangeable, so it's great having extra options at your expense when it seems like you have nothing to wear, whether she likes it or not.

8. You can roast each other.

When you're close as you guys are, you know you can make fun of each other without someone getting their feelings hurt. When you do something stupid, you know she will never live it down, just like how you will constantly remind her of that one time that really embarrassing thing happened to her.

9. You are very protective of her.

Like previously mentioned, you can roast your sister and poke fun at her all day. However, if someone else tries to, they've crossed the line and you won't have it. You're quick to come to each other's aid and help whenever help is needed, and you don't like anyone who has ever done her wrong. You will never like the girls who have done something mean to her or the boys who have ever made her cry.

10. You have a confidante.

You have saved each other from potential trouble with your parents, and have covered for each other numerous times when needed in different situations. You have a ton of things that you look back on and laugh at because you can't believe you did them, and you two are the only people who know about it. Of all the outrageous things that have and might still happen, you can rest assured that she has your back and won't ever tell anyone, because she knows you'd do the same for her.