To have a sister is to have a best friend no matter what. Friends may come and go, but your sister was the first one to call you ugly when you first got braces and the first one to hug you tight when you got accepted to college. There will always be the bond that makes your relationship unlike any other.

Here are a few secrets you definitely share with your sister.

1. If she ever broke anything in the house

Rule number one in the sister handbook is to NEVER tell on your sister. If she is the one who broke that expensive, antique pot that has been in the family for generations, then you blame it on the dog. Don't have a dog? Get one.

2. Who your first kiss was

Shhh, don't tell mom.

3. The embarrassing amount of times you guys call each other

After you find out your grade on that impossible test you took last week or even after you found out where you and your friends are going for dinner, who do you call? The one person who will always pick up the phone just to hear about how you just woke up from a nap. That's all. Goodbye now.

4. Girl drama

Friend: "Don't tell anyone."

Me: "OK!!!"

Me, five minutes later, talking to my sister:"You will NEVER guess what Becky just said about Rachel... !!!"

5. Guy drama

*Sends screenshots to sister every time he answers*

6. Who she is interested in at the moment

Boyfriends, hookups or even the guy who doesn't know you exist will all be discussed in detail several times to your sister. You don't know her, but she knows you.

7. She's the one who must approve all Instagram posts and captions

Your sister is the only one who will honestly tell you if it's not Insta-worthy or if the caption is sub-par.

8. Adventures about the night before

"So tell mom that I was home by 12 and you heard from me that entire night..."

9. You both can agree when your parents are annoying you

"Call dad and tell him to stop being annoying and put money on my card...please, he likes you more..."

10. When you use your parents' credit card without them knowing

We can all agree we love getting those texts when your sister tells you she just bought a shirt for the both of you to share.

Me: How much?

Her: It's on mom and dad, don't worry.