Good Evening.

It's a yaoi manga.
And all I remember about it is that one of the main characters (the uke I believe) dumped his girlfriend from school.
I do remember it was after the first volume and after he realized he was in love with the seme, but I think that he was going out with them both for a while. I think the manga has over 3 volumes.

If anyone knows please let me know. Thanks in advance.

edit: I remembered that the seme was old(er) and the uke was a high school student.

Maybe Boku wa Konomama Kaeranai ?

No, it's not, thanks for trying though.

Yume no Kodomo?

Yes, that's the one :3 Thank you.