I think I figured it out. I didn't realize you could equip items from the shop menu, and so the event that checks to see if you bought a bra only works if you buy it and don't equip it. I'll patch a fix for it next time I update the game, but in the mean time if you unequip your bra and go into the shop menu again, then exit, it should work. (I got it to work using your save, at least.) Let me know if that doesn't fix things for whatever reason, and thanks for letting me know about it!