I wasn't really happy with the way things ended in "Divide & Conquer", so in my own little world, I think something like this could have happened.
The Key to the Room
It had been several days since the zatarc retesting of Sam and Jack, and the sad death of Martouf.
Those days were very busy sorting out the events of that day with investigations, reports needing writing. SG1 remained on earth – no missions scheduled. Things were slowly getting back to normal, or as normal as they could be around the SGC.
Jack and Sam were polite to each other when they saw each other, but busy with their own duties. Among all the other things of recent days she had to think about, Sam couldn't stop thinking about what they had admitted during the re-testing.
She had reached out and barely touched his hand with her fingertips as she suggested "this doesn't have to leave the room". Jack had looked down at where their hands were touching and trapped hers in his while no one was looking and asked if she was okay with that. She hadn't had a chance to reply, since everything had blown up at that point and gotten very confused.
It didn't mean she'd stopped thinking about it. She didn't want Jack to think she'd been suggesting they just forget what they'd admitted, but she couldn't think what to do about it, either. There were just too many things going on at once, and as usual business took precedence over personal feelings.
On her way home one evening, she stopped at a hardware store for some items she needed to fix some cabinet hinges in her kitchen and while there, passed a shelf with keys on it. Stopping to browse through them, she came across one that made a "light bulb moment" go off in her mind.
The next day, Jack entered his office to find a small box on his desk, a pretty white ribbon wrapped around it. Obviously puzzled, he picked up the box and shook it.
He turned it over and over, and finally took the ribbon off and opened the box.
Inside was an old antique brass key. Under it was a scrap of paper. He took both out, and unfolded the paper. There were a few words on it:
"In case you ever want to revisit 'the room', this key will open the door."
It was signed "S", followed by a little smiley face.
A grin slowly spread across Jack's face. He put the key and the note back in the box, and tucked them into a safe place in a drawer in his desk.
The next morning, Sam entered her lab to find a small white box on her work table. Wrapped in a pretty white ribbon, the box looked a lot like the one she had left on Jack's desk the previous day.
She was hesitant to even touch it, fearing slightly that he was just returning it and dismissing the whole thing.
It took her some minutes to dredge up the courage to open the box. In it was an old antique copper key similar to the one she'd left for Jack. With a slip of paper under it.
She tentatively took them both out, unfolding the paper. A few words on it read:
And "Some day."
It was signed, "J" … and a smiley face.
A sigh of relief escaped her, as a smile spread slowly across her face.
They would be okay … for now.