Was I Just Out of Line?

So, yeah, I just broke up with my long-term partner of two years. We both agreed it was the right decision for us after a lot of talks and introspection over the last couple months. But now that we're officially not together anymore, there's this unresolved tension that's been building since before the breakup. There were hints and signs of it while we were still dating, but I pushed them aside as my insecurities. Anyway, right after getting our breakup paperwork signed yesterday, we went back to his place to sort out some shared stuff and clear things out a bit. As we were packing up his side of the room into boxes, I found myself thinking about all the times we'd done it in there, on that bed, against this wall, every corner of that space holding memories of us together. I couldn't help but stare at him as he worked, and before I knew what was happening, I had my hand on his thigh. It moved up slowly until it was resting right next to the bulge in his pants. His eyes met mine with a look that said everything, shock, desire, maybe even hurt? 'Sorry,' I said quickly, pulling back. But instead of anger or discomfort, he looked at me like he wanted more. 'You don't have to stop if you're not ready,' he whispered. So, we did it right there and then, on that bed where so many memories lay, his naked body under mine, pressing against him with every thrust until the physical tension spilled out between us in moans and gasps. It was intense, but also strange given what had just happened; this wasn't our last night together or a final goodbye, it felt more like violating something sacred. Now I'm left wondering if that was crossing too many lines. We haven't really talked about the future or boundaries yet beyond staying friends for now, so I don’t know where we stand emotionally or what kind of physical limits there might be going forward. Is this something other people do in similar situations? Am I overthinking this?