Do you lend your books? Are any out on loan right now? Do you have any that have been loaned to you? Do you put a time limit on these? Do you think people should make an effort to read the loaned book quickly?
My short answer would be: It depends…
I both lent and borrowed more books among friends in the past than I do now. One reason is that there are fewer people now that I see regularly, and most of the people I discuss books with these days don’t even live in the same country!
I have some experience from far back in the past of people not returning books… Keeping them for years, or even for good. Whether I’d lend a book to someone now depends on what book, and who’s asking.
Right now I think I’ve only got one book on (private) loan myself. I’ve had it for a while as it’s part of a series and I’d not read all the previous ones yet. But my aunt knew that when she lent it to me… (It’s probably in turn now next time I feel like holding a “real” book instead of the Kindle.)
Generally speaking, if someone asks to borrow a book from me, I’d probably expect them to read and return it sooner rather than later, if nothing else was said. But if it’s the other way round - if I say to someone “this is a good book, borrow it if you like” - then I wouldn’t automatically assume them to dive right into it.