So, this morning my husband had recently came back from the gym and was sitting on the floor. Our 7month old Yorkie, Mac, ran up behind him, threw up his leg and peed on him!

This has never happened before and I'm not sure what it means. Is Mac saying the hubby belongs to him? Is Mac mad at him? He is trained to use a potty patch and rings a service bell to let us know when he needs to go out. And the hubby had let him out to potty a few moments before.
Has anyone else had this happen? Should I worry?