This is really frustrating and I hope you guys can help. I'll try my best in describing it.
Okay, here it goes. I've only read the first few chapters.
The first characters to be introduced are younger brother, younger brother's friend, older and brother and older brother's friend.
The main couple is the younger brother (seme) and the older brother's friend (uke).
Things I remember:
They met at the school's roof top.
The younger brother can usually tell when someone is trying to sneak up behind him except for when the older brother's friend does it.
They hooked up for the first time in this abandoned building (their hideout(?)). I'm sure one of them said, "Can I see your penis?" or something like that and they started to fondle each other which then turned into sex.
The were being chased by some delinquents at one point and ended running far away from school.
The younger brother is taller than the older brother's friend.
The older brother's friend has black shoulder length hair (I think)

ARRGGHHHH, I CAN'T REMEMBER. and this is my first time asking and am having this irrational fear of no one replying/seeing this.

cant believe im still around

I think its this one: http://www.mangaupdates.com/series.html?id=6024
but i dont know how to make it into a link.. sorry first time responding 😀 hope its the right one!!

Dog style

That was surprisingly fast ._.
As soon as I saw the words 'Dog Style', I knew it was it. Thanks, both of you.
and aliceboule, you can learn from here. Funny how it's my first post, and your first response XD

cant believe im still around