During the movie night on the couch, you have to pick the dialogue option "No man can refuse a blowjob in the morning," or something along those lines.
I dont really know how you unlock 31 and 32. I just did all the stuff with Nova earlier and got a scene where you chase her down the hallways and punish her in an empty classroom. I don't think the amount of slaps you give her in the first punishment matters. 17 and 18 are easy. You just have to use the vibrator on Mrs. Jackson when she's giving a speech by clicking the button until the number reaches 100 or whatever the maximum was.