Prospective tenant angered over inquiry about second person

[Mark Forest]

We have a house that is becoming difficult to rent. We had a prospective tenant who makes a lot of money as a plumber. On the phone he only mentioned that he needed the house for himself because he does a lot of work in the area. He was actually filling out the credit report when my wife asked him if he would be living alone in the house. He said that while he would be responsible for all rent he wanted his 21 year old nephew to move in with him because he was having trouble with his parents. I told him that any adult would have to be listed on the lease and would also require a credit check.

The man became a little angry and told us it did not make sense because he would be paying 100% of the rent and the nephew would be allowed to stay for free. He did not think the nephew should be any concern to us. Our lease states that anyone staying longer than seven days requires approval of the landlord. Did we overreact?