We know we'll be zero-for-two in your penis's book when we say this, but trust, we have you best interests in mind. Okay, we'll just say it: Don't have sex with her or anyone else. You're officially on a hump hiatus.
Hear us out. You can date other women (and you should), but you shouldn't be using the space apart as an opportunity to sleep with someone new (or old, for that matter). If she hears about it, or even suspects it, you're relationship status will be cemented. In stone. And concrete. And every other impenetrable rock substance.
Remember that classic Friends episode where Ross protests, "But we were on a break," as an excuse for sleeping with someone else, and Rachel gives him the cold shoulder for, uh, several seasons? Don't make Ross's mistake. Hold off until you've given up, because if you do reunite, you know the first thing she'll ask is if you've slept with someone else. You don't want to start a new leaf with a lie, do you?