No, I don't let my friends borrow my clothes (same thing for money and my bags). If anything, if I know I am no longer interested in wearing a particular clothes anymore, I may ask them if they want it prior to sending it off to charity. I would never let anyone borrow my clothes for sanitary and maintenance care reasons.
WARNING: PARANOIA AHEAD - I don't know if I am the only one but I don't like trying on bottoms (jeans---underwear shopping is the worst) at the store knowing endless people have tried it on before me. I just fear I may catch something so I always carry a sheets of paper towels and use it to avoid direct crotch contact. This started years ago when I saw this lady come out of a dressing room asking her friend how she looked in these white pants. Her friend said something like "wow, you look real good and no panty lines." The girl wearing the white pants says she doesn't like wearing underwear because it's "too restrictive." I was shocked. From that time on, I always carry something as a protective shield. Heck, if my mom banned me from letting others borrow my comb out of fear of contracting head lice. You can see why I do what I do to avoid catching another type of lice.