Romance in The Rain between a half-sister and the other sister's prospect husband (let's say they're going to get married-even if they're not dating-if the first sister doesn't snatch him).
Love Scar between a new wife with her brother-in-law who's her ex.
Love Keeps Going between an ex-girlfriend and the ex's younger brother.
Bread, Love, and Dreams between a 'half-brother' and an ex-crush or ex-girlfriend (they're not actual brothers apparently).
Moon Lover Scarlet Heart Ryeo between 8th prince's ex-kinda-dating and 4th prince.
If it include fake relationship then:
My Cherie Amour between a younger brother's fake girlfriend (but the younger brother's feeling is real) and the older brother.
Wedding Impossible between the older brother's prospect wife (marriage contract) and the younger brother.
