A house for Rent...

We have decided to move - we are in a 3 story townhouse now and that just doesnt work with two small kids - not to mention we dont have a backyard really. So we are looking for a house to rent. Jonathan hears me calling people, "Hi, I'm calling about the house for rent." Then later we say that we are going to look for a house for rent. Well, Jonathan believes that we are looking for a house for Rent, that is, that Rent needs a house. I figured this out when we went to look at one with a realtor and as we were leaving he looked at her and said, "Bye, Rent." I tried to explain to her what he thought, but I think it just offended her. This morning during our Wednesday morning semi-ritual of going to the donut shop he saw a woman come into the shop and said, "Mommy, there's Rent." It wasnt the same lady, but looked a little like her, to a 3-year-old maybe. I tried to explain to him today that we were looking for a house for rent, not for Rent. "Rent is not a person, Jonathan."
"Mommy, Rent is a boy?"
"No, Rent is not a person. You know how we go to the store and buy things. Well, you can buy a house too. If you dont want to buy it you can sort of borrow it, that is called renting."
"Rent is a girl?"
I guess if I cant explain to him why he should poop in the potty, I should have realized that this was a lost cause...