We heard you liked sublets so we subleased your sublet. This is one of the realities of modern renting, especially in a big city with a competitive market. It’s also especially popular with students, who might only need a room for a couple of months at a time. It can be a wonderful thing. If you’re the original renter, you might get the chance to save some money while you’re away. If you’re the subletter, you get a place without all the hassle of officially being on a lease and buying a whole new set of furniture. A lot of these deals are done under the table, though, so you don’t always have a lot of recourse if it goes wrong. 

Things also get tricky if you have roommates. You might be fine with a stranger staying in your room, but your roommate has to live with them, and they didn’t necessarily choose it.