The regular clothes on monday isn't a bug. In fact, the regular clothes will get skimpier at a certain moment. What you have to do:
1. on monday morning, breakfast - there will be a moment when the MC will say " may be... " when he drops his fork. At that moment, search on Shantrel's leg, and you'll see a hotspot " tickle ". click on it.
2. Go to college and get back to her in the evening. Choose " money " and the scene will progress. Search for a hotspot " up " when she's bending = Second Happiness
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If it doesn't work, make sure you bought the bikini for Shantrel on Saturdays - in the work area, search for " BadGirls " Clothes Shop. Do the scenes available with the bikini until you see " the end " message and check again the dream sequence.
Good Luck.