Hey that makes sense to me. I was getting gender and sexuality mixed up.

If sex is : male/female
then gender is : masculine/feminine
and sexuality is : hetero/homo/bi(etc?)

So you can be a boyish girl who likes men.
or a girly guy who likes guys.

Disregard my attack on OP. Didn't read description before commenting.
My other points still stand. The "trigender pyrofox" bullshit is exactly what I'm saying in the "tl;dr" section.

It's a variant on the Minutemen ending. Found a guide to get it on Youtube. Here's a link: www.youtube.com/watch?v=OUFEeYdQnVc
Basically, you start off on this by completing the BoS quests before completing Reunions (including talking Brandis down and convincing him his backup will be here soon). Then you do Reunions and Dangerous Minds. After this, Shadow of Steel and Tradecraft unlock. It's important that you ignore these for a while as you focus on the Minutemen, because you need to use the Minutemen to gain access to the Institute.
Once you're in the Institute, kill someone to get kicked out before you start the second quest. Just don't even start the second quest. Don't talk to Father after meeting everyone. If you're feeling particularly good, choose a victim that deserves it (someone in the Synth Retention department, perhaps?).
After getting 86'd, completely ignore Form Ranks and Defend the Castle. Avoid the Castle like the fucking plague, and go help out the Brotherhood. Do all their quests until Show No Mercy, but please, for the love of god, don't fucking do Show No Mercy. Don't even start Show No Mercy. Why? It fucks with the BoS's AI settings and makes them highly aggressive, to the point where they occasionally mow down civilians for no fucking reason, and it blocks off the secret ending.
AFTER helping the Brotherhood, do Form Ranks and Defend the Castle. This should give you the option to do the Nuclear Option. Don't do it yet. It's not the right time.
You know what it is time for? Helping the Railroad. Go do Tradecraft through Randolph Safehouse 6, then do the Nuclear Option on behalf of the Minutemen.
This lets every good companion live, because face it, the Courser isn't anywhere near fun to have around.