Watching 2nd ep. until now weird to ship an engaged woman with a high school kids. Let alone the other characters in drama, looking at the way the high-school kid and math teacher being shipped together in the absence of her fiancé and her blatant not being interested in him mentality screams the idea of cheating and possible cheating and PEDOPHILIA. Do not forget my emphasis on the word "possible", i am not saying he's her love interest but, that is how it is made to look.
Also, i do not understand y the makers of K-drama has to showcase women being uninterested in the current spouse as normal thing? I mean, if u r not interesting in marriage or getting married then y let urslf reach that stage in the first place? Nobody is forcing u to marry that particular person. Stop waiting for sm1 btr and until then sticking around with current option. If u don't like it then just leave. Don't indirectly normalize cheating. Be honest to urslf and ur partner. Atleast, ur partner then can find someone btr than u.
Also, in the first episode itself we know who most probably is going to be painted as the villain here, it most probably has to be her current fiancé as always.