The first time, it was loneliness. It was an awful thing to be that alone, to be cut off from everything a person knew, everything that was familiar and comfortable and safe. Oh, yeah, Jack had a pretty good idea what Teal'c was feeling. So, he'd done it. One night, when Teal'c had confessed to the smallest part of loneliness, one night when the ache in Jack's own chest had become unbearable, when all the pain and loss had simply piled up too high, they'd both cracked. Weakened. Given in. Reached out.
When he woke up in the morning, the ache was gone.
The second time, it was grief. Jack cared a lot about Daniel, they all did, and losing him--even thinking he was lost--hurt Jack in places he hadn't thought could be hurt any more. And Teal'c, Teal'c was still carrying around a load of guilt about Sha're, blaming himself for having helped Apophis choose her, blaming himself for Daniel joining SG-1 to find her. Blaming himself for Daniel's death. One more thing they had in common. The chance to leave that grief for a while, to bury it in something so human, so basic, was a chance neither of them had been willing to give up.
When he got up the next morning, the grief was better.
The third time, it was comfort. After everything that had happened on Apophis's ship, after nearly losing their lives and the lives of everyone on the planet--after shooting Skaara, feeling him die in his arms--Jack had felt drained. Empty. There was nothing to fill him, nothing to keep him going after the adrenaline drained away. He was just a shell, a man walking around with nothing inside his skin but bones and flesh and other meaningless matter. He'd needed to feel alive again, to hold and touch and know that there was more to him than the soldier.
In the morning, he felt comforted.
The fourth time, it was lust. Plain, simple, old-fashioned lust. No catalyst, no reason, just the need to get into each other's pants and have at it. They didn't even make it to the bedroom, just did it half-sprawled over the kitchen table, careless of the discomfort--and the pizza--not to mention the ludicrous contortions they'd had to make to get the job done. Jack had started laughing about halfway through, and had only stopped when he'd needed the breath back for breathing.
Afterwards, he was satisfied.
The fifth time .... The fifth time, it started to break down. The fifth time, Jack realized he'd run out of excuses. Once or twice, even three times, he could pretend that it was casual, two old soldiers in need or want or lust or whatever. But after that time, when it had happened for no reason that he could find, no reason other than that he wanted to be with Teal'c, wanted to be close to him, to make love to him .... That's when he'd realized that he'd made nothing but excuses from the start, lies that would still let him pass it off as nothing more than comfort, nothing more than sex. Excuses to let him justify keeping Teal'c at a distance afterwards, to selfishly avoid the thought that maybe it wasn't just friendship, or even desire. That maybe it was something that fell somewhere between like and lust. At least alphabetically speaking.
That morning, he knew the next time, he wouldn't be making any more excuses.