Okay so this doesn’t really count as a headcanon, but I’ve been thinking about their reactions to the break up and how they dealt with it and what that means about them. With the exception of Mark, Leslie doesn’t really dwell on her break ups, as horrible as they were. That’s to say, it doesn’t really take her a long time to get over them. And unless the woman was really great, Ben never truly pined for an ex either, at least not in the way he pined for Leslie.
So the fact they were both so heart broken after the break up says so much. They missed each other so much, and they were both clearly very lonely, even if they dealt with it in different ways.
Okay here are some actual head canons:
Leslie drunk dialed him one night but Ann took away the phone and hung up before he could answer. He didn’t call back and Ann deleted the sent call off her phone.
Unlike Ben, who didn’t send his texts, Leslie did. And there are a lot of them, most of them not even about them. “I’m watching Stargate like you said to. I love Samantha Carter!” That kind of thing. He never responded, not even to tell her to stop.
Leslie thought that they just needed to get through the campaign and then they would be free to be together. It never occurred to her that Ben wouldn’t want the same thing.
And it wasn’t until she saw him with Shauna that she realized it.
Ben went on a date. Not with Shauna, but with someone Chris set him up with. He even kissed her but it was all wrong and that’s as far as it went.
He thought about quitting and leaving so many times, but Pawnee was already becoming home to him, and really he just didn’t want to leave her, even if he couldn’t actually be with her.
He almost didn’t go to the park, but he got very curious.