I think it's a one-shot but I know it was a short story and less than 5 chapters. It's about a woman who has a job of arranging weddings for couples (along the lines of marriage and couples type of career). She has a boss whom she doesn't really like. In the story she's also waiting for her boyfriend to come back from...somewhere since he just left with all her stuff. And then I think that's why the main girl started living with her boss temporarily. Later, one of her clients are crying during her wedding because the husband is missing (I think). Then the main girl tries to comfort her but the bride just gets upset and yells back. The husband shows up and the bride apologizes to the main girl, all's good.

And somewhere in the middle the main girl's boyfriend comes back and goes like "Looks like you're doing pretty good" (not the exact words but similar), and the main girl hesitates to whether she should be with him because she likes the boss guy now.

I hope this is useful info even though it sounds a bit mixed up and confusing. Thanks in advance!

Omg I found it! It was Datte Ai wo Shinjiteru!