When do you call it quits?

We all had a fair share of friendships that we kicked to the curb, and sometimes it hurt deep down or it was for the best. In certain friendships you know how to deal with the person so you let things be, but it comes a time where you can't take it anymore, and that's when you call it quits. For example, you have a friend that has been your ride or die, but this person is jealous, and envy's what you have, so they become fake towards you. In cases like the example that was given, that's not a friend. A person that has jealousy towards you will drain your energy, and that person doesn't want the best for you. Another example is the person throws shade at your success because they see you are doing well, and want you to be down on their level. Two faced people are similar to the scenario by cheering you on at one point, but the next telling someone else "Oh she thinks she's all that" which is shade. The hardest friendships that you have to let go are the long term friendships because at one point you all were the best of friends, but it took a turn to the dark side. Being someones friend for so long to one day turning on you is a stab in the back, and you never guessed it coming. Though, if you are stuck in a friendship that drains you, steals your joy, belittles you, then you have to get out of it. Calling a friendship quits is not easy, especially if you have history, but you have do what's always best for you. You never want to surround yourself with a person or people that damage your self worth.  Friendships should have characteristics of positivity, inspiration, motivation, and open mindsets to understand each other. Always be true to yourself to know when it's time to say good-bye, and just love them from afar. 
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Question: Would you give the ex-friend a second chance?