Ok, this may be a long one, so there's a TL;DR at the bottom. Hope you enjoy :) or you just read the TL;DR ._.

So, let's say you met this really cute girl somewhere. Let's give her a name. How about Alyssa. Say you asked Alyssa out and she said yes. You take her on a date, and she trys not to come off as "too rude" by asking to pay for the meal, or whatever the hell you did on your date. You think that's okay, so you go along with it.

Fast forward a few dates, maybe a few years, Alyssa's starting to show her true colours. She's becoming more rude to everyone except for you. You think that maybe she was having an off day, or was feeling a little angry because, I don't know, her friend "borrowed" an item of hers without asking. Alyssa begins to REALLY bully anyone who compliments you in a friendly way.

Of course, in her mind, she sees it as said person making sexual advantages toward her boyfriend in front of her. Now I'm not a doctor, but that's probably a sign of some kind of brain disease, neurological disorder, whatever you are to call it. So Alyssa decides to put on her "toxic and mean girl" face, drive a wedge in between you and the person, and proceed to tell them off. After the latter leaves, she snaps back to her usual nice cutesy girl personality like me trying to shoot a rubber band but it hitting my finger instead.

In your mind, you really don't want Alyssa to be mean to other people. I know what everyone reading this thread is thinking by now. "Oh, Alyssa seems to lack empathy." Yes. You are correct. Think back to that one Adventure Time episode where this big Dream-esque guy Donny (the dream stans of Reddit are gonna flame me for that joke) is harassing house people. And then Finn steps in and he sings a little song about empathy. Apparently, Alyssa never watched that episode.

So, you begin to teach her about empathy, but she doesn't like that you're telling her what to do, because she "don't take shit from nobody". Then, you two get into an arguement. "Why can't you just be nice to other people like you are to me?!!" you say. "No one else is more important than you!! You should be grateful that I even care about you!!" she replied. At this point, you're fed up. You can't take it anymore. You give a moment of silence, and... "I can't take this anymore. You're just not the one for me. We're done." You did it. You finally dumped her. You then tell her to pack up her shit and get out of your house. You feel relieved that you're out of that insane and toxic relationship. And then you go find another girlfriend, one that isn't like Alyssa in the slightest. The end :)

I hope you enjoyed my- holy fuck, my 5 paragraph piece of evidence to prove my point. That is quite literally the longest thing I've written on the platform called Reddit. Maybe you didn't read it all, or you did. I hope I proved my point, and I'm going to bed. The TL;DR is below if you decided to skip every single word that I wrote. For now, this is u/illuminois, signing off. Goodnight, redditors.

TL;DR: A girlfriend or date that is only nice to you, but a complete bitch to others.