Family staying.

A couple of months ago my wife and her sister were reunited after a number of years of not speaking. My sil and her son were on the verge of being evicted. So my wife invited them to stay with us. My sil soon got a job and contributes when she can . Her son on the other hand does nothing but watch tv in his room and play computer games. This is driving me crazy. He did have some chores to help out around the house, but always needed to be reminded to do them. We gave up asking him . I’m a patient person. This is stretching my patience. My mental health is suffering. Advice?