<human>: Can you give me a shortened version of the text?

We broke up in January. 
And it was just awful.
But since then, we've been on and off seemingly every other couple of weeks. Now it really looks like we could be getting back together, but during our most recent hiatus, I slept with someone. 

Now I'm agonizing over whether or not I should tell her. If I tell her, it might just hurt her and ruin everything forever. If I don't, I'm not being totally honest with her. 

Part of me says, I was single, and that is my business. But the other part of me wants to be honest and I just don't know what to do.

Please, I just need some advice.
<bot>: 2 year relationship ended in January, off and on ever since, we might get back together, but I slept with someone during an off time and don't know how to go about it.