"If we had a keen vision and feeling of all ordinary human life, it would be like hearing the grass grow and the squirrel's heart beat, and we should die of that roar which lies on the other side of silence." - from George Eliot’s Middlemarch
Don't get me wrong. I still love Sansan and I am totally thrilled and diehard about Jamie/Brienne.
But a part of me can see a strange thing between the Kingslayer and his young able-bodied Knight of the Flowers. Loras is so like a young Jamie. Jamie both envies him and wants to hit him over the head. And maybe teach him a lesson. By fucking him hard? One can only hope. It would be the ship with the prettiest pecs and abs in all of Westeros. Renly was handsome surely, but he's no golden knight like Jamie Lannister.
Okay, I just totally see it happening one lonely day in the White Tower. Jamie is soooo over Cersai by this point. And Loras, well he'll always miss his Renly. But this won't feel like a betrayal of vows to either of them.