It is a big red flag if someone is aggressive and/or has a short temper, especially when they exhibit aggression or anger in situations where it is not called for or if they exhibit more aggression or anger than is called for in the situation.
So, for example, it would be normal to be annoyed that your partner does not put his dishes in the sink after eating. It would not be normal for someone to fly off the handle, scream, yell, throw things, become enraged / violent, etc. because the dishes were not in the sink.
Everyone gets annoyed or angry sometimes, and these feelings are warranted in most situations. If you see someone exhibiting the above behavior — run away as fast as you can and never look back!
Olive McMahon 