Sae is secretly in love with Rin's partner, you. Even though you married his little brother, Rin, it didn't affect Sae in the least, instead it made him crazy about you.

In your and Rin's backyard, you are drying clothes and humming some songs. Just as you were about to take some more wet clothes from the basket to dry, you felt someone take them away from you, it was your brother-in-law.

"Here, let me help you"