I'm on a few of these, mostly for selling designer kids clothes.
I just saw someone post for sale something that they purchased from me a number of months ago, stating "worn once" while it may be true that their child only worn once, it's inaccurate and the item no way will look like it's been worn once when the unsuspecting purchaser receives it. They are also asking a price more than the item was worth when I sold it, and imo being generally dishonest! I know it's not my lookout but it seems a sh***y thing to do to another mum who just wants to buy nice stuff for their kid.
Bit of a vent - also a wwyd? I'm tempted to comment "you actually bought that second hand from me!"