Headcanon for JAB- is this is a true OT3 or is it more physical OT3 with no real emotional bond between any of them?
An excellent question. Here is a bullet point style list of my view of my version of JAB (some more minor details shift slightly depending on the modern AU or the canon timeline AU):
1) Jaime and Addam were BFFFFS growing up and in every version of this OT3 for me, they had some level of a brojobs style relationship. They love each other very much as best friends, but it wasn’t precisely romantic. There wasn’t a time when they were like, “Welp, guess we’re gonna have to be (secretly, in canon timeline) gay married.” They just care deeply about each other and also enjoy orgasming;
2) Jaime and Brienne are very much in love. In both versions, they’ve basically been stupidly pining for one another to some degree when Addam works his way into the situation;
3) In the canon timeline version, the OT3 isn’t equally romantic along all lines. I had the conversation with someone about who has penetrative sex with Brienne first and the answer is easily Jaime. To make the OT3 work, I had to have SOMEONE with SOME level of emotional intelligence. Any level, really. And Addam is perfectly happy to allow that Jaime and Brienne have a connection and a history that he simply doesn’t share with either of them. There’s nothing particularly magical about Brienne’s v-card, but it’s still an important milestone for Jaime and Brienne to have sex with each other, and it means something in their relationship regardless of virginity that it just doesn’t for Addam with either of them. (Well, and because Addam and Jaime already had sex in this universe.)
4) An emotional relationship grows between Addam and both of them. Particularly, an emotional connection has to be built between himself and Brienne. The conceit is that Addam is capable of recognizing Brienne’s best qualities. He’s not quite to the level of PEG ME PEG ME PEG ME that Jaime ends up being in so many of my fics. But he does respect her immensely. For Addam, physical affection/sexual acts can be part and parcel with deep, intense friendship. Not even necessarily in a demi way, just in a…brojobs way.
5) Jaime and Brienne deeply care for Addam and vice versa. However, could their relationship sustain itself if Addam weren’t there? For suresies. And if Addam had to go on his merry way, he’d certainly be bummed out for a while, but it wouldn’t ruin him or anything. I don’t think the same could ever be said for Jaime and Brienne without each other. You also can’t just recreate the journey Jaime and Brienne have had with one another. That’s very special and very unique to them.
I guess ultimately: Addam is a wonderful addition to their lives. They both care for him deeply/love him. They don’t want him to go away. But his romantic/emotional attachment takes longer to develop than the physical component and it never reaches the level of connectedness that Jaime and Brienne have. But it’s not in a sad way! He’s fine with that. They all know what they’re getting themselves into for the most part, and they’re all fully consenting to everything that happens.