Didn't really "lend" our old trailer to our son as he had put in for half of it when we bought it - it lived at our place and we used it all the time. He "borrowed" it once and it got slightly damaged in a huge wind storm - he was so upset - but it could have happened to us in the same circumstances. He fixed it. And now he has the trailer full time as we now have our new one.
Also offered it to one of our other sons to use and he said "No Way - my friends just wouldn't respect it".
Nice to know we have brought them up to respect other people's belongings