We've all encountered those people that only seem to notice your existence when it's convenient for them. They make terrible friends because they fade in and out of your life, only coming back when they need something and leaving as soon as they don't need you anymore. Here are some common things part-time people are guilty of:

1. They text you when their bored, but stop replying once they find something better to do.

This is especially annoying if you were texting about something important. Then again, they only reply when something is important to them–not you.

2. They cancel last minute because they would rather hang out with other people.

That's fine I didn't really want to go anyway. I'm rewatching the entire series of Parks and Recreation.

3. They make plans with you and then "ghost," you the day before.

It's crazy how you can't reply to texts but Facebook is showing that you are online. I guess you aren't missing after all.

4. They are experienced in the "Sorry I missed your call. I was in the shower," excuse.

No one showers for three days straight. At that point just be honest with me.

5. They claim to have never gotten your text but read receipts say otherwise.

This is especially funny when they text you first saying that they never got your text. How would you know that I texted you if you never got it?

6. They say they are sick but are out with people on snap chat.

Perhaps, a doctor visit is in order. Especially since you are sick every day of the year.

7. They go to bed early but post on instagram three hours later.

I feel pretty confident that you can't post selfies while asleep. If you can, that is an incredible talent.

8. They drop off the face of the earth for six months, then come back into your life just when theirs isn't going great.

Sorry that you only need me when you have no one else. I refuse to be a back-up option, though.

9. They need you in a breakup, but ignore you in the next relationship.

Pushing everyone away when you are in a relationship is going to make being single a very difficult experience. This probably explains why people cling to unhealthy relationships.

10. They never ask how you are.

A conversation is one-sided when you are the only one asking questions or attempting to keep the conversation going. It's not hard to throw in a "What are you up to?" every once in a while.

If any of these sound like one of your friends, you might need to cut the cord.