Step son works cant pay much board !Should he do more chores to compensate ie grass i work 6 days a week i1 ho?

i work 6 days a week 10 hours a day he has weekends off and is home everyday at 4.15 and 3.15 on fridays ,his mum works, does all his ironing washing cooks for him etc ,he doesnt go out plays on xbox (even though he runs a car ) .All i ask is for help in the garden ie grass cutting maybe once a week ,and any other small jobs they may come up . I have quite bad lungs and struggle with heavy work . oh and hes a fit and able 18 year old