As advice site Barking Up the Wrong Tree explains, some people are simply too toxic to include in your life. 

However, if you label everyone who ever wrongs you as “toxic,” you’ll start to lose friends fast. Instead, apply the rule of three to identify when the bad behavior is just part of who they are. If they lie to you or let you down once, it might just be a fluke. If it happens repeatedly, it’s a pattern. Harvard psychologist Martha Stout explains it this way:

One lie, one broken promise, or a single neglected responsibility may be a misunderstanding instead. Two may involve a serious mistake. But three lies says you’re dealing with a liar, and deceit is the linchpin of conscienceless behavior.

Of course, there may be some exceptions that you can be conscious of. If they drop the ball on some critical responsibility a few times after a family member dies, that might be understandable. If there’s always some family member that died whenever they let you down, they might be lying to you. Watch for patterns in their actions, rather than focusing solely on their words.

This Is How To Deal With Psychopaths And Toxic People: 5 Proven Secrets | Barking Up the Wrong Tree