I am with you, I feel your pain. It will end now.

When Trevor left the vault he left with a girlfriend and both settled as far north of Boston as they could and even started a family. However, the baby died of SIDs and the girlfriend was never the same after that. They tried to make it work but it just wasn't working out so they broke up and she left Boston.

((She and the Sole Survivor found each other outside of Boston and both got together, she's helping her girlfriend raise Shaun along with Dogmeat and Codsworth.))

After that Trevor just went from place to place. Yes, it hurt a lot that he'd lost his baby but Trevor's very cold and calculating, he's the type that removes the emotional element from just about everything. Doesn't mean he doesn't care or that he isn't capable of love, he was just raised that way. Most people in that vault were. The only person he ever told about the baby was Loke.

Then after wandering around he actually bumped into Preston and some Minutemen fighting off some BoS stragglers and he was kind of enamored with the fact that people—regular people—had decided to fight back and not let the Wasteland just tear them apart so he joined the MM and fought alongside them. That's how he joined the Minutemen and learned about them. At that time Preston was the temp GA and Trevor was adamant on getting to that role. To him it was kind of a pet project, the second resurrection of the Minutemen army.

After some time (a lot actually) Trevor gained Preston's and Ronnie's approval, trust, and respect and so he was given the rank of General. And once that happened Trevor's pet project came to life. He saw the potential and wanted to heavily militarize the ever loving fuck out of the Minutemen starting with giving the MM the old world ranking system that the U.S. had before the bombs. Given his history he was very familiar with it all.

This was seen as a good thing by some and bad by others. Some saw him as too radical, too brutish, and too out there while others saw it as the boost the MM had been lacking for a long time and he was pretty fair about it. If people wanted out they could leave, no questions asked. However, they couldn't re-enlist. Those that stayed were very devoted and in a way this decision made other people actually wanna join the Minutemen.

As the GA (general of the army) he met Aleksandr and while he was still a private there was sort of a spark happening between them and it was something Trevor didn't really think about but that Russian won him over. Despite rumors he did not favor Aleksandr nor were his promotions exchanged for sexual favors, the ex-raider just earned his way up the food chain on his own merits.

Trevor, Ronnie, and a few of his captains had come into contact with a raider gang thanks to Aleksandr's ties. The leaders: Tyrone and Lamar (they're from England and sort of the English version of the Enclave with members being descendants of MI6 and SAS so the pedigree is ripe with potential) decided to join the Minutemen and keep an eye on Nuka-World and raider activity giving Trevor a head's up whenever they're up to something stupid.

Then he met Jelani through Aleksandr and while Alek didn't really care about the age gap (let's be honest, Alek is immature as fuck to the point where you'd swear he was younger than Jela) Trevor was kind of unnerved by it so there was no interest there at first. However, both of them were very similar in a lot of ways and had a ton in common with a little sprinkle of friendly rivalry when it came to marksmanship and sharpshooting and from there feelings started to grow and soon the three of them were a couple.

This is where Trevor's coldness and calculating nature comes into play in a good way. Like, I said before Jelani hadn't told either of them that he was pregnant so on that day both Trev and Alek were shocked. It was obvious that it wasn't Alek's but also not Trev's since Jela was still not sexually active with Trevor yet (it takes some time for him to open up that way to others). Anyway, they figured out the pregnancy was due to what had happened to him and while Aleksandr was excited about the baby Trevor had to keep him in line and remind him that Jelani hadn't decided what to do about that and that in his honest opinion it would be best for both Jela and the kid if they were handed over to people who could actually take care of them.

In the end he respected Jelani's choice to keep him and once Trevor was sure that that was what Jelani really wanted to do he went all in. Dad mode instantly on. In fact, he agreed with Jelani when he said that he didn't want the kid to ever know the truth so they all just said that he was his and Trevor's. He also helped when Loke and Uthorim had reunited with Jelani who got it in his head that if Lo and Uth found out that Erik was his and not Trevor's that they'd be beyond pissed off at him for getting pregnant despite it not being his fault.