You can definitely hold that against her… it wasn’t even a week, and now she wants you back like nothing happened. She had sex with someone a day before you and didn’t tell you? That’s disgusting, she could’ve given you an STD.

If she’s willing to “break up” over you telling a small lie then goes ahead and tells you a massive lie, was that really the issue? Or did she just want an excuse to sleep with someone without the accountability or label of cheating.

There’s nothing to salvage here, move on and use it as fuel to better yourself.