[identity profile] oasis6028.livejournal.com 2010-08-31 02:35 am (UTC)(link)
One of my all time favorites - Dark Roots by the fabulous Morpheus.

http://www.mags-nificent.com/MSW/MorF/S4.htm

[identity profile] ch33rylips.livejournal.com 2010-08-31 02:36 am (UTC)(link)
http://morpheusqaf.com/DarkRootsIndex.html

Totally must read.

[identity profile] qafkinnetic.livejournal.com 2010-08-31 02:37 am (UTC)(link)
The Wedding Present by Predec2
http://www.fanfiction.net/s/6220271/1/The_Wedding_Present

It's a WIP, they only started a few weeks ago.

[identity profile] sarahdipity221.livejournal.com 2010-08-31 02:38 am (UTC)(link)
Dark Roots by Morpheus fits your request almost perfectly. It's very well written and pretty lengthy. You can find it here: http://morpheusqaf.com/DarkRootsIndex.html

I also really like besame_bj's fic Mirror which is also lengthy and has several sequels. In this one Brian still has the same dad but finds out he has a twin brother who was given up for adoption. Here is the link to the first chapter: http://besame-bj.livejournal.com/26956.html

Hope this helps!

[identity profile] court1429.livejournal.com 2010-08-31 02:40 am (UTC)(link)
There's also one where Carl is Brian's dad, but I don't remember any details.

[identity profile] balrogtweety.livejournal.com 2010-08-31 03:30 am (UTC)(link)
[livejournal.com profile] edom has one called Going After Him. It can be found:

http://www.midnightwhispers.ca/viewstory.php?sid=995

It's a WIP.

[identity profile] barbygirl18.livejournal.com 2010-08-31 08:48 am (UTC)(link)
Hi! I found two fic

Where I Belong
http://www.mags-nificent.com/MSW/TriF/WIB.htm

I think in this one jack isnt brians dad but i'm not sure

Be Careful What You Wish For
http://www.mags-nificent.com/MSW/Collaborations/Careful.htm

[identity profile] mysid.livejournal.com 2010-09-01 01:12 am (UTC)(link)
I'll second the motion on both of these.

Although Mirror doesn't technically meet the conditions of your request, it does meet them in spirit. As the fic progresses, the adoptive father of Brian's twin eventually takes on the role of father to Brian as well. Brian does indeed get the family he deserves.

[identity profile] mysid.livejournal.com 2010-09-01 01:17 am (UTC)(link)
No, Jack is Brian's dad in "Be Careful What You Wish For." Brian finds out that Jack had a brother who was gay, and that Jack had cut his brother out of his life when he found out. Brian's uncle contacts Brian post-Jack's death and shortly before his own. It's more of a "Brian and Justin meet in a different way" fic.