Brian fuck a man behind justin back

[vie-hero.livejournal.com]

So there is a story that bugging me these past few days
I tried to search it but failed because i forgot the title and the author and the story too
The only thing i remember is brian and justin try to be monogamous i think then brian meet this man from his work (steve i think the name or evan i can't remember) and fucking him behind justin's back
So one day justin come to brian's office to celebrate (maybe?) and saw brian fuck this man and kissing him too! Justin get angry and throw a glass or a bottle of wine to the wall behind briam and that man. After that justin ran from the office. I only remember that part because it hard to read brian fuck man other than a trick. But i'd like to torture myself and read it again :)

Thanks!

Found by solkeera
one big family by Draccone