Writer - Slave to my imagination

Jaime doesn't realize from what we see of Tommen, he absolutely would choose the former. Tommen loves Loras because he's the big brother he always wanted as opposed to Joffrey to borrow from Terminator 2: Judgment Day:

Watching Tommen with Loras, it was suddenly so clear. The Knight of Flowers would never stop. He would never leave him, and he would never hurt him, never shout at him, or get drunk and hit him, or say he was too busy to spend time with him. He would always be there. And he would die to protect him. Of all the would-be brothers who came and went over the years, this man, this Knight of Flowers, was the only one who measured up. In an insane world, it was the sanest choice.

Compared to the abusive Cersei and negligent Robert, Tommen would want a father who is interested in him, and supports him the way we see Jaime do in AFFC. Of course, Jaime grew up in a family obsessed with power with Cersei preferring a crown to him, his father wanting his grandchildren to sit the throne and disowning him when he refuses to leave the Kingsguard and be his heir. Jaime never wanted power, he wanted to be the next Ser Arthur Dayne and love.

Jaime never actually hopped off the self loathing train, so I can totally see it happening.

Re: the effects of LSH on Jaime’s character specifically, I think the whole incident will force him to confront what he did to Bran in a serious way. So far he’s always justified it to himself and kind of shrugged it off in his internal monologue. He doesn’t think about it. But going through what will probably be a traumatic trial in which he’s forced to confront the creature grief and many, many injustices turned Catelyn Stark into, and his own affiliation with the people who orchestrated the atrocity that was the Red Wedding, and the fact that he inflicted the first blow on Catelyn and house Stark by pushing Bran and crippling him (and it was all a domino effect from that)… I think it will be somewhat of an eye opener for Jaime.

"What are you doing here?"

"Something stupid. Get behind me." He circled toward her, putting himself between Brienne and the bear.

"You get behind. I have the sword."

so like he starts off the video pointing out a handful of lines where he agrees it is blatantly apparent that Jaime and Brienne are sexually attracted to one another. but then we get this:

But will they get together intimately in the books? No, I don’t think they will. See, and this is just my opinion, I could be totally wrong, but I think it’s because they don’t need to. I don’t think it would do anything for their characters, I don’t think it’s that type of story, I don’t think it’s that type of relationship. And the best way I can describe it, this may not make sense to other people but it makes sense in my mind, is that this relationship, which people have often said is the juxtaposition of the Beauty and the Beast story. You know, beauty, beast, whatever. And that story - and that type of story - is more about love rather than intimacy. And I know those things can go hand in hand, but due to the nature of the world, and due to the nature of the characters, I can’t see them having a serious - even a one-night-stand type of thing - successful intimate scenario. I think Jaime would feel too vulnerable, similar to Brienne. But what I can see is an attempt… maybe drunk, maybe they just go like ‘screw it, let’s go for it’, and it’s very awkward, and they’re like ‘no, this isn’t right’ type of thing. I know I may not have explained it right there, but that’s just my opinion. 

I find this slightly fascinating because I think he's actually verbalising what I've seen many other readers do when they look at the facts, and realise yes, this is a romance, and yes, there are already strong sexual undertones - but they cannot reconcile what is objectively on the page with how they personally feel about the pairing, and try to kind of intellectualise why courtship and intimacy don't really apply to Jaime and Brienne the same way they might any other romance.

like:

I don’t think it would do anything for their characters

...... why??? why wouldn't sex do anything for two characters who are sexually attracted to one another, and have a drawn out arc getting closer to one another?? one has only had secretive sex with one person he's now effectively divorced, the other has never had sex and has never imagined that she would get to enjoy sex?? so like..... what do you mean it would do 'nothing' for them, it would HAVE to do something

I don’t think it’s that type of story

there is sex all over the place in ASOIAF. Just a few POVs who have sex in their chapters include: Tyrion, Jon, Daenerys, Catelyn, Asha, Cersei, literally Jaime - so why would there not be room for Jaime and Brienne specifically to have sex?? it is VERY much that type of story.

I don’t think it’s that type of relationship

you said yourself they are sexually attracted to one another and seem to agree it's romantic. so... why wouldn't it become that type of relationship?

people have often said is the juxtaposition of the Beauty and the Beast story. You know, beauty, beast, whatever. And that story - and that type of story - is more about love rather than intimacy

..... i mean it's a children's fairytale so they do tend to leave the fucking out but here's a thought: George doesn't

and I know those things can go hand in hand, but due to the nature of the world, and due to the nature of the characters

due to the nature of.... their world?? where people fuck all the time??? or our world?? where people fuck all the time?? also the nature of their characters, they both have sexualities and desire each other, YOU HAVE TO EXPLAIN WHAT YOU MEAN

I can’t see them having a serious - even a one-night-stand type of thing - successful intimate scenario. I think Jaime would feel too vulnerable, similar to Brienne. But what I can see is an attempt… maybe drunk, maybe they just go like ‘screw it, let’s go for it’, and it’s very awkward, and they’re like ‘no, this isn’t right’ type of thing.

here is what I find very telling, and what I also found very telling in D&D's JB 'sex scene'. I think we are seeing awkwardness imposed upon JB from the perspective of the reader here. like yes, I agree, their first time would probably be a bit awkward - Jaime has experience with only one person, and Brienne with no one, but I'd say perhaps the majority of 'first times' are awkward. but if it's a consensual encounter between two people who are sexually and romantically attracted to one another..... you have to explain, on what basis do you think it would be 'unsuccessful'? what is going to poison this encounter? what is fundamentally 'not right' about it?

Dungeon rat Jaime

Bald (hides nothing from the gods) Jaime