I borrowed my roommates Speedo a few times over the course of a few months when we lived together. Sadly he very rarely went swimming, and the trunks got thrown out about halfway through our time living together. If I'd known what day he was having a clear out I would have salvaged them for myself, haha.
I borrow Speedos from my dads wardrobe from time to time. Again, he doesn't know. He did catch me with his trunks in my gym bag once, but I explained it away by saying I was behind on laundry.
