Tools, money not my wife. If some one asks me I will usually say yes. If they abuse the privilege well that's their bad Karma and I won't offer again.....and being very judgmental I find that I will write that person off as not being worth my time.
That probably sound harsh but there you go, I'm deeply flawed.:-
Its the ones (tools etc) that don't come back which are annoying.
You go to use something, can't find it and realise "hey I lent that to someone" but can't remember who it was. I dont even get the satisfaction of feeling sanctimonious.:(