(read the original books here)
The way I’ve been reading and re reading these books these last few weeks… And how I wish there were more fanfics about it.
My headcanon is that after 6 years, Simon starts doing couple things without realizing, touching Jeremy for no reason, just a passing hand on a hip, a squeeze of the shoulder. He’ll kiss Jeremy hello and it’s so ingrained, he will do it in front of the team and not even realize what an earth shattering moment that is. Jeremy will raise an eyebrow but take in stride and not mention it, even if he does notice everyones reaction (probably at poker night).
Even after 6 or 7 years, Simon would probably be the last person to acknowledge he's in a serious monogamous relationship with Jeremy and he has no plans of changing or ending that state of being.
His team (and Annabelle of course) would notice how he calls Archer more frequently, to talk about whatever, be it his current boring job of babysitting a senator getting death threats, to complain of his new neighbor, how he went to this party and the food sucked (not to mention he rejected all offers, male or female, without a second thought) or even to try to coax Jeremy into dropping by again cause it's been 2 months since he last did and it ended too fast cause Simon was called back to work. The words "I miss you" are never spoken, but to whoever is listening (Jeremy and, because he's been calling during work, a blushing Nate and a chill Johnny in the team room) it's clearly there.
Thoughts of changing apartments are also coming to mind more frequently. A new (bigger and better) apartment and a second key. It's not that he wants to give it to Jeremy, he just wants to avoid a neighbor calling the police about the thief.
There's also that nagging feeling of domesticity he has been craving with Jeremy. He sometimes entertains the idea of Jeremy leaving the crime business and... He always stops there. Late at night, he does think of Jeremy and of Jeremy and him and where they are going. He doesn't think about the future together as much as where they're going.
It surprises him when he goes out at night with some of the guys he did the FBI training with and when asked if he's single, he denies it, saying he's involved. It surprises him because it's a mere statement of fact. It's not a lie or a deceit to get them off his back. So he tries it again and says out loud he's been in a relationship for some time, years. He evades any further questions but it's there.
He ends up admiting it to himself later as well. And when that barrier is broken, he will admit to wanting more. Ultimately he will get the new apartment, he will give that second key to Archer warning against attempts of breaking and entering (not asking him to move in just yet). Archer will start showing up more often, leaving stuff around the house (a toothbrush, his froufrou shampoos and shower gels, a shirt or two).
They'll join poker night together and banter all the time. But everyone will see and know that they're more than just Archer and Simon now...