I’ve ridden with my son and he used one of my mountain bikes because he was out visiting.
On a ride with my brother, we swapped bikes for a while.
The only bike that was stolen, was one I had loaned out. It was an old GT MTB that was given to me. I went through it, rode it for a while. I wish I still had it so others could use it, but I didn’t have a lot invested in it.
But at this point, I wouldn’t loan any of my, or my wife’s, bikes out.
John