Ex's Sneaky Reappearance...

So I was in the middle of moving my last box out to the dumpster when I saw her car pull up. My ex-girlfriend, Sarah, who I thought we were both ready to move on from a couple months ago after about three years together. She's got that same old charming smile though, like she can just roll back into your life whenever and nothing has changed. She walks over with a bag of clothes and some books, apparently planning on staying the night? I was still in my pajamas from sleeping at her place last night and hadn't left yet. She says it's because she’s not really settled in to her new apartment yet, but what does that even mean? We catch up for a bit about our respective weeks... I was just trying to be polite as I packed the rest of my stuff up. Then out of nowhere, Sarah slides her hand under my shirt and starts playing with my nipple, right there in front of all the moving boxes. She says something like, “I don’t want you to leave yet,” but her words are kinda muffled because she’s already pressing me against the wall, kissing me aggressively. It was clear what she wanted next, so we go into the bedroom. And let me tell you... it's been a while since I've felt this good between my legs. She gets on top of me and starts grinding her pussy down hard on me, making those little noises that drive me crazy, yeah, I'm just gonna say it, she's got that special something when we’re together like this. As soon as Sarah comes off, there’s no stopping the rush of wetness pooling around my dick. She pulls away and sits back to watch, running her fingers down my abs, spreading my legs wide with a smirk before climbing back on me again... I won’t even try to explain why it felt so right. And here's the thing: after we’re both spent and exhausted from it all, she just starts getting dressed again. Like nothing happened at all and maybe we’ll catch up next week or something. Did that really feel like closure for her? I don't get women sometimes... So, am I the asshole for feeling like this was a big misunderstanding on my part? Do people ever get back together after months apart to just 'talk' about stuff? Or is she playing games with me now? And... what does that even mean in terms of where we are as a couple going forward? Am I just a one-night stand now for her? She's not exactly saying anything clear on this end. ...