In the scene between Sarah and Carl in Sarah's bedroom, just before the phone rings (1:09:00 or there abouts) Sarah just slid of the straps of her dress and you can see her bra and bra straps and they kiss again but then the phone rings and the shot goes back to a back view of Sarah and you see there are no bra straps and it is obvious that carl couldn't have taken her bra off in that time.