I'm going to get angry with my friends because they didn't invite me for a night out
Why didn't they include you for the night out?
I don't know.  I'm really good company.
It is understandable to be hurt when your friends left you out of plans. Maybe they thought you were busy.
I wish they had asked me first.
Maybe they forgot to invite your, or they could not because there were too many people. You can ask them about it if you want to know. I'm sure they won't forget you again.