Because, Chancer had successfully made Lisa and Olivia willingly to skip their classes, very naughty. Not to mention making mom leaving her office at 14.00 hrs, no wonder she got fired later on.
This is how Chancer make Olivia change her default schedule;
It reads, On every Tuesday at 13.00 hrs. No need to attend your math class Olivia, better to meet Max in his room instead. This persuasive suggestion from Chancer is so strong, it make Olivia come to Max without even thinking. No dating, no dinner, no meeting and not even small talk will be necessary. Looks like Olivia enjoy it too.