Is it ok if I have very inappropriate feelings for someone?
Who is it that you have feelings for?
The girl who I worked with. It makes me mad when she kisses her boyfriend.
You can't help who you have feelings for but it is good to control yourself. You could interfere and damage their relationship if you let your feelings be known.
I will try but I can't promise anything.
It's good to hear that you are going to try to keep your feelings to yourself and not interfere with the relationship. Try to find someone else to have a relationship with so you can stop focusing on your workmate.