Responses
http://www.mangago.me/read-manga/airyouran_gakuen/
(one of the pairs)
This is it!! Thank you so much ^_^
It was a oneshot. The seme & uke were supposed go on a date when unexpectedly the seme was given the responsibility to look after a kid. So even though the uke grumbled a bit, the seme manages to convince the uke to take the kid along with them on their date. The kid was very attached to seme, so he got jealous of the uke and kept pestering him at any chance he got. At on point the seme went to buy something and left the 2 of them alone. At that time the kid said something really insulting to the uke, so the uke got really pissed and pushed the kid(or it might be accidental. i don't clearly remember). So the kid falls down. The seme sees this and slaps the uke without even giving him the chance to explain properly. The uke gets really pissed and leaves them. Later the seme hears the real story from the kid and goes to apologize to the uke.
So anyone remembers this? I will be REALLY grateful if you do! Thanks!!