tardisjournal did this wonderful drabble called Last Call which you have to read first, otherwise you would not understand mine.
After that last line, I couldn't help myself adding a bit more to the story. Here we go:
Jack threw the water into the next plant pot and put the glass on an empty table. Without a last glance he walked out of the door. Coming here had been a mistake. He didn’t actually remember consciously making the decision, but somehow he had ended up in this of all bars.
It had been almost a week now, and sometimes he wondered how things would be different if he had Ianto allowed to stay. In the weeks before his betrayal came to light, Jack had had the feeling that there could develop more between the two of them. More than his usual office flirts.
But after that awful day he had felt used, he wasn’t able to tell anymore whether Ianto’s little attentions had been genuine, or just a diversion. So he had made the hot-headed decision to retcon Ianto and get rid of him for good. Out of the base, out of his life.
Only, it didn’t work that way. He couldn’t stop thinking about the “what if”.
The only consolation he had was that at least Ianto was safe now. No alien trouble would befall him in this bar, as long as Torchwood was watching. He would live a happy life, not knowing anything different.
And Jack would need to find something to distract him from events he couldn’t alter anymore.
Sometimes he wished he could retcon himself.