I'm mad at my friend because of their boyfriend
What did their boyfriend do?
The way he looks make me mad when he shows up for a date.
I feel like sometimes I get angry about little things too, but for things that are not affecting you personally, it is not right to get mad or to be angry with someone else. Your friend's boyfriend did not mean to offend you or harm you, that's why you should not feel angry at them.  They did nothing wrong.
I'm always mad and have a spitting attitude.
In that case, it is good that you came to me first before you got mad at your friend's boyfriend.  It is not appropriate to blame other people for minor things, but if you feel like this often, you might want to talk to someone.  They will help you get your feelings under control.