It's called Honto Yajuu
Love that manga
No that is not it, Honto Yajuu is about a yakuza and a police officer, not a son of a police and a police officer.
I've read that one, where the kid comes back to the police officer after returning home, and he wants to live together; I just can't remember what it's called.
I still don't know its name but I do remember that the kid had bad grades and cured the police guys insomnia or something like that.
Ah-ah! It's http://www.mangago.me/read-manga/oyasumi_darling/ * ...tho it isn't a police officer son, but a rich family heir. Isn't it?
OMG! I almost forgot it, thank you so much Veneka.
There is a manga just like this one except longer and the seme is the police officer. I can't recall what that mangas name was though. :(