Jack's eyes roamed lazily round the Tardis platform as he thought about all that had happened in such a short time, all the events that had led him to Rose, the Tardis… and the Doctor. He knew he should be more worried than he was he was, virtually stranded with a nineteen year old girl still wide eyed and naive about the worlds she found herself in, on a ship that was more mysterious than any living being he had ever known bar one… that one being of course the doctor, Mr time lord, nine hundred years old, "I am the smartest and my screwdriver is still way better than your big gun" doctor.
He had considered disliking him or finding him irritating but it didn't take him long after being rescued to realise that disliking the doctor simply wasn't an option, he was just so damn likeable, like an overgrown puppy with floppy ears but not really like that because he never been attracted to a dog before and the doctor was right in his estimation of twenty-fifth century men sexual inhibitions had never been something that mattered to him the way it did in Rose's time sex was sex and love was love didn't matter who you found it with so long as you did. Also attraction was attraction, he had liked Rose for her warmth and enthusiasm and well she's hot so that helped but he was attracted to the Doctor for a whole different set of reasons, ones that troubled him because he still remembered what had happened the last time he had experienced said feelings for someone else.
Normally Jack was a love 'em and leave 'em type but when he got like this last time he kinda forgot about the leave 'em part, but then there was a war and there was a bomb and there was an apartment afterwards there was no apartment, no world and no one left except for Jack who was somewhat ironically saved from death by a certifiable suicide mission to try and intercept the bomb. He never got to the bomb and he never saw Frankie again… that'll happen when your lover disintegrates along with the rest of the planet.
And now here he was again and it was nearly all the same things as that last time, great smile, wicked sense of humour and so smart that it was inevitable sexy but the difference was that this time his attractions were clearly unrequited. Not that the doctor and he didn't get on great, they had a lot in common time lords time agents but every time he saw Rose's hands intertwined with the Doctor's it was obvious there was nothing coming between them and he didn't want to try because, a) it wouldn't work and b) it's good to see friends happy… okay, okay maybe there's a little c) threesomes are waay fun! Lurking around somewhere in his mind also but he knows what he's gotta do this time skip the love 'em and get straight to leaving before it was too late.