I'm going to jerk off to pictures of my friends and lie about it to my so.
Why are you going to masterbate to pictures of your friends?
Because it's fun and I get turned on when I see them.
Being turned on by other women is fine and can happen from time to time, but masturbating to their photos is a step too far. If your SO finds out then she will definitely be hurt and feel like her trust has been broken.
You are mad, my SO is fucked up and only cares about herself.
If that's true, then this is something you should talk about with your SO. Hopefully that fixes the issues that are being had in the relationship.