There are two people I would loan a gun to. One of my Brothers and one of my cousins. They are the only ones I trust to treat it correctly, both safety wise and how to take care of firearms.
I learned long ago not to loan anything to my Dad that I wanted back the same condition I loaned it to him. He's my Dad and I love the guy, but he does not take care of his stuff.
But, then again I am VERY particular about loaning and asking to borrow anything. My Dad has a bunch of four wheelers and always invites us to go out riding with him. We have gone once because he took the WHOLE family out. Any other time we don't go because I don't want to fix anything that breaks while I am riding it. Soooo.. I don't ride it.