I rarely loan out tools too, but the one exception in my neighbor, he can borrow anything he wants. This guy is so anal he takes great care of everything. He once borrowed a tool from me that was old and well used, he broke and replaced it with a new tool without even asking me. I told him it was not necessary as the tool was old, but he was determined to replace it.
One week end he planned to pull the engine from his pickup to put in a clutch. I offered him my shop as I was going out of town any way and I would not be working in the shop over the weekend. He hesitated, I told him to don't worry about it and gave him the key. Sunday when I got home the shop was spotless, all the tools were put away where they belonged and he even scrubbed the floor. It was cleaner than when I left! Now if I could get him to come over more often!
I would probably let him use my wife if he wanted too, she probably would come back in better shape! Greg