help to find a bl

Any help would be appreciated.

The main character is blond idiot that doesn't realise he's in love with his high school friend. That friend confesses to him on the last day is school and they have sex, then the friend ghosts him hard. Years later he bumps into the friend when he's picking up his niece from nursery. He's completely shocked that the friend seems to have a kid. Down bad and still oblivious to his own feelings he comes up with a mildly insane plan to make the friend fall in love with him and then reject him I think. I also remember there was a bit from the friend's point of view where without the internal monologue it's harder to tell that the main character hasn't got two brain cells to rub together.