my ex and i got playful

ok so my ex and i recently separated but we are still kinda friends and stuff. so last night we were just hanging out and talking about old times. then she started telling me how she missed the way things used to be between us, you know, before the relationship fell apart. it was like we both felt this sudden desire to go back to those days. i mean, not literally but more like recreating that vibe or energy again. so we decided to play a little game. i dont know how to explain it exactly but basically we acted out some of our old fantasies and stuff. it was wild and intense. she even let me tie her up and blindfold her and do some dirty things to her, which was kind of shocking cuz she usually hates that kinda thing. i felt so turned on and excited though. afterwards we just talked about how weird but good it felt to be together like that again. i am not sure if this is normal or if i should feel bad for getting such a rush from it even though we are separated now. what do u think? am i the asshole?