You have to talk to the guys in the hallway at noon. It becomes available when the game tells you to go to the shower at noon after chatting with Sasha. Go there and pick the option to leave Sasha. Then, click on Connie and Jean. You will ask him to kick a bucket of water. The next day at noon click on them again. It will make him distract Luke so that you can be with Sasha alone.
Good luck.