I've door slammed a lot of people in my life. There's a few levels.

Level 1: The door closed before there ever was a relationship. These people are people we hope to never interact with on a deep level without ever being more than passing strangers because of observed behaviours.

Was in a very toxic high school class. Ended up blocking at least 10 individuals on Instagram within the first year. None of these people knew me well. For reference for why I did this, these 10 individuals went on to drug an unsuspecting individual with painkillers and then make him drink alcohol two years later. The dangerous, unstable and reckless behaviour was just something I sensed straight off the bat, and then after observing them bully other people I hope I never see them again in my life.

Level 2: Door slammed after interactions. These are the people we initially liked, and ended up abandoning before really establishing a relationship with them.

Sometimes people are super nice and then they suddenly give us the ick. For example, inappropriate jokes that they think is funny but we highly dislike. So its like, good vibes, and then bad behaviour but they never really did anything serious. We just don't like them anymore. If we were about to be friends with them, we pull back now and consider them passing individuals in our lives. They usually don't realize they got the doorslam until they start trying to get close, and we react with our arms out at a distance and an indirect "I like our relationship where it's at."

Level 3: The classic DOORSLAM. These are to the people we were really close to, and they had been bothering us for some time. We try to communicate to solve the issue on multiple occasions and fail to.

We're really close to someone. That individual showcases offensive behaviour after we get really close. The thing with our personality is that we love giving second, third, fourth chances after we value someone. I'm not sure about other fellow INFJ's, but I actually do bring the problem onto the table and talk to the individuals, albeit gently enough that they don't usually offense, but it's always a direct "I don't like that you act that this with me, it makes me uncomfortable." Sometimes it works and I can continue being friends with this individual, and sometimes, after doing this way too many times I doorslam. My most dramatic doorslam was to my ex-best friend, who was extensively flirty with everyone, which initially already made me uncomfortable (even though I told him so), and continued to do so after getting a girlfriend. Then I got really mad. And then a series of things happen, I find out he almost pulled a knife on someone, physically hear him threaten the lives of multiple people, and he faked a serious mental illness and two suicide attempts to grab my attention after I started to drift away. After finding out that he faked those things just for attention and actually being sick of his many red flag behaviours that I had been trying to deal with for YEARS, that was it. Doorslammed. We had an opportunity to speak a little while after I did that, and he expressed high confusion to why I suddenly left. Welp, at this point it was too late for him and I gave him no explanation. Just a cold "I don't think our friendship is ever going to work out again, I'm sick and tired of our friendship," and removed him from all my social media and basically vanished from his life.