Kiss Shitara Kowareru no wa Wakatteita.

“If you cry, I will no longer hesitate." Aki is exhausted by her husband's increasingly controlling behaviour. After returning to work, she happens upon her ex-boyfriend, Shuji, whom she was once hopelessly in love with. Everytime Aki and Shuji meet, she is troubled by his enduring love and understanding towards her. If she hadn't kissed him again, nothing would have come crumbling down, but... (Source: MangaGo)