Past Love reappears before female lead

Any where the male and female lead are either together or close to being together, but then the female lead's past love appears and that causes feelings to come back. It begins to destroy her relationship with the male lead. In the end though, she finally decides to focus on loving the male lead after seeing what it's done to him.

I've seen In Time with You (T and K), Witch's Romance, Good Job, Good Job

I have only one... so sad

https://mydramalist.com/132-do-re-mi-fa-so-la-ti-do

 No1:

I have only one... so sad

https://mydramalist.com/132-do-re-mi-fa-so-la-ti-do

That looks good.

 CherryBunny:

Witch's Romance

I already mentioned that in my main post.

 fanitha:

Pride

Seen it, but thanks.