It completely depends on the kid, neighbor, or friend. If they have repeatedly demonstrated the skills, knowledge, and respect required to ride and care for it properly, yes. My kids aren't there yet (one might, one won't). I have a neighbor who rides the 'hood with his family on decent-quality city/MTBs, but I don't know enough about his skill level to trust him with any of my bikes. I have a number of friends who I would not hesitate to loan any one of my bikes. All of them have been riding and racing for at least a couple of decades, and have had tons of experience with their own high-level machines. I have other friends that are a definite "no".
__________________
"Swedish fish. They're protein shaped." - livedarklions