Scratches on his back!!!

Recently I saw scratches on my husbands back . I saw them when he got home from work. When I confronted him about it he acted stupid so I took a picture and showed him. And he said it was my 5 month old baby really? Then he changed up and said it was my 6 yr old son . Now he said it was a tree . Here's the pi tire of the scratches tell me what y'all ladies think?

This lady is the lady he recently cheated on me with. I think it might be her since he had a relationship with her for over a year. 😞