Family and Real Estate Investments Do Not Mix

My husband and I bought in to the real estate market when it was at its lowest. Over the years, we have made a good return on these investments for the most part. The only property we consistently had trouble with was the one a family member was leasing. We finally got her and her boyfriend out of the house, but not before they did a great deal of damage. Now my husband has offered to let his son move in. This is no better in my opinion. I need to find someone who can explain to my husband that an investment is only good if you are paid. He wouldn’t put up with this behavior from other tenants so we shouldn’t have to take it from family.