Wrong joke

A traveling salesman's car breaks down, and he walks over to a near by farm. He knocks on the door and the farmer appears. "Excuse me sir, but my car broke down about a mile down the road, and I was wondering if you had a place I could stay,just until morning, and I....." The farmer says, "Well, I can let you sleep in the barn, but you'll have to sleep with my two sons...." The salesman says, "Sons! I must be in the wrong joke!"