Spoiler In Words for Marry Me, Mary! Episode 8

After it was revealed that Mary's marriage to Mu Gyul was a fluke, Jung In's and Mary's dad pushes for the Jung In X Mary wedding. Mary, who's all the while bias towards Jung In, forces herself to open up her heart to him. After hearing about Jung In's painful childhood experience, she tells him not to suffer anymore and consoles him.

Mary's birthday is the day of their engagement (how convenient for the busy Jung In! you can celebrate this day one shot in the future). After receiving Mu Gyul's congratulations through SMS, she sets out to meet him. The rest of the band members were at the entrance. They lock (huh, WTF?) the couple up and runs off. 

Mary wants to tell her mom about her upcoming nuptials, thus Mu Gyul (who's stuck with Mary) had no choice but to follow her to her mother's grave. Mu Gyul is mad that Mary agrees to marry Jung In despite not loving him. Well, she is unhappy with his careless attitude towards love too! And so they both unknowingly fall in love with each other...

Chloe Says: Aww, look at her! Have you seen a sadder bride? Looking into those Puss-In-Boots' eyes, how can you not stop her, Mu Gyul ah!