It makes no sense for Sarah not to have taken Jordan back. They already had enough drama last season and she only broke up with him because of his secret which she now knows about
... I see a lot of hate towards Sarah. Not really sure why, the dominating characteristic of high school relationships (in my opinion) is that nobody really expects them to be serious, and therefore when dating doesn't work out it's easy to stay friends. I had a lot of friends date each other for six months or even a year and then break up but still stay close. Sometimes it's hard on one half of that, sometimes it isn't but they all get past it either way.
After watching this episode I have a feeling Jonathan might cheat on his girlfriend with his ex after what he just found out, a love triangle might happen if this continues
No, Jonathan remained faithful. Eliza did try to make a move on Jonathan, but he backed off and told her he was already dating Candice. And when Eliza still tried to make a move on him, Jonathan simply left and backed away, so Jonathan's a faithful boyfriend to Candice.