At one point in the main game the three future spouse options of A Foretold Affair wear clothing that's not exactly the same as their usual fare. With quality pieces like those we couldn't help but give people the option to use them all the time. With this DLC you'll be able to freely swap back and forth between the normal and alternate outfits at any time and control individually which of the three characters wear what!
Using alternate outfits will not change CG images or the script, only the character sprites will be altered.
Nothing is perfect I'm afraid.