I remember reading a manga this past year or last year where the little brother decides to get revenge for his sister because her ex cheated on her. So little bro dates and leads on the ex and is planning on leaving him only the ex gets super attached to little bro and begs him to stay. Little bro leaves only for ex’s big bro to get involved and blackmail little bro telling him to get with the ex and make him happy or big bro will tell little bro’s sister?? Something like that, anyhow little bro gets together with the ex and I remember one of the last panels of the manga being the sister on a date and it pans to her phone where’s she’s messaging a bunch of different guys.

Any ideas at all would be great!!

I had given up on anyone answering this!! This has been bothering me for months!! Thank you so much!