Everytime we invite julie out, it rains. lets not invite her next time.

Well, if you are asking for the meaning of this sentence, then it would mean that Julie is not fun to have around. For instance it says, “ Everytime we invite Julie out it RAINS.” This shows that Julie may not be a fun person to invite or she might be the root of the drama. Another clue would be “ Let’s not invite her next time.” This shows that Julie is not being invited because everytime she goes it rains, or in other words everytime she gets invited it gets into trouble and people fighting with each other. So, this would be a “Post Hoc”
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