1. They expect you to be a mind reader.
They don’t want to be a bother and state what they want out loud, but they also want you to magically know what that is. It’s very easy to unintentionally offend an introvert because they won’t tell you what the boundaries are — just expect you to stay within them.
2. You have to be their guide.
When you’re going to a party or an event with your introvert you’re expected to take on the role of translator, stay by their side and introduce them to people and help them make conversation. Left to their own devices they’ll probably play on their phone in the corner all night, and that’s fine, but you know they’d like to at least feel included for awhile so you need to be there helping it happen.
3. They won’t tell you about a conflict until they’ve reached their boiling point.
An introvert can get mildly annoyed about something you do that isn’t a big deal — you wouldn’t mind doing it differently at all. The problem, however, is that they won’t tell you so you don’t know to change. They’ll wait until the problem has them over the edge and they are exploding with anger and it’s not a tiny conversation anymore.
4. You’re always leaving events before you’re ready.
An introvert’s idea of a fun party is showing up at 10 and leaving at 11. And that’s fine, but if you’re in a couple or you drive together it means you either stay later at the party knowing they are exhausted or you leave far before you’re actually ready to go home.
5. They’ll blow you off to do nothing.
It’s one thing when someone declines to hang out with you because they have really fun alternative plans, it’s another when an introvert does it… just to stay home and watch Netflix. You know they need their time to recharge, but you can’t help but be offended that you’re less fun to be around than their MacBook.
6. Sometimes you feel like you’re forcing them to be your friend.
Introverts can be loud and lively with people they know well, but most of the time they are quiet and you can feel like an unwelcome guest in their secret inner world.
7. It’s hard to tell if they really like who they are.
Why can’t they just speak up and tell you what they don’t like? They tell you it isn’t a weakness thing, and you want to believe them, but how hard is it just to speak up! Sometimes it’s hard to reconcile your affection for this person with their seeming lack of affection for themselves and you aren’t sure if they need your help to become more confident or if they are happy they way they are.
8. They are difficult to compromise with.
This isn’t because you don’t want to compromise with them, it’s because getting them to say “no” or “I don’t like this” is like pulling teeth. When they do express their opinion, they only do so because they are at their breaking point with it, at which point it’s impossible to compromise or have a discussion about it because they’re in an emotional state of mind.
9. Some introverts look down on everyone else who “need” to be around others because they think this means they are weak or attention seeking or whatever.
You can never be sure your introvert doesn’t feel this way about you.
10. They perceive small things as “rude.”
For instance, salespeople who are just trying to do their jobs or people who prefer to talk on the phone. You wonder which of these small crimes you may have unknowingly committed.
11. At some point, you are going to hear about their grievances from a third party.
Not wanting to initiate a conflict, an introvert will blow off steam by venting to a friend instead of telling you what you did wrong. This feels shitty when you had no idea, but apparently this mutual friend knows all about it.
12. It’s a lot of detective work.
All of a sudden their behavior has changed a little bit and you realize they are probably mad at you for some reasons but you have to list all the interactions you’ve had in the past few weeks and try to figure out which one of those things was not good for them. Communication is the foundation for every good relationship, and yet… they will never communicate with you about uncomfortable subjects.
13. They can have a victim complex.
It’s hard for an introvert to assert themselves and so they can feel forgotten or resentful of the fact that, “the squeaky wheel gets the grease.” But there’s nothing to be done to help them, no one can read their minds and predict what they want without them saying it, out loud. 
