How to hide my self harm cuts?

I need help hiding my self harm cuts. I promised my girlfriend that I d stopped cutting and she wanted to check my arms and my legs tomorrow to make sure of that. She said if she finds any new cuts on me she d break up with me and I did cut. I feel so ******* stupid and I need help with hiding them so she doesn t break up with me. I don t know if there s another way besides makeup as I am a male I don t have any make up. Please please help me