It is about those clothes that are given to you during the game, some are work clothes, others come from dialogs and questlines you are going through, the question is : why some will remain in your inventory, while others not ?

The (very pretty) frilly maid outfit you find while doing cleaning for Riley, that she gives to you and commands you to wear when you clean the sorority is not to be found. Another point to fix : when you are wearing it on the right side display, it should also take off your socks/stockings/tights and cover properly your legs so it would look much nicer.

Some other examples of clothing we (I at least) would like to keep in the inventory to wear again : 

-the "Slut" t-shirt you receive  when you are all set up and made up, the old Frilly Shirt (to have both the old and the new) and there could be others that I don't think of or because I haven't gotten them yet, that I have seen in the game's folders.