new to this stuff

ok so i am a personal trainer and i started dating my client last month. she's in her twenties, super fit but always wants to improve more than i can really help with. we both decided to try something different, like adult ageplay or whatever u call it. basically she wanted to play the role of a younger athlete and me as this overprotective coach type. it was kinda awkward at first bc we had known each other in a purely professional way for years before dating but we were both into it after that first week. one night, i got all intense about her performance during our workout, like really pushing her limits which made her act out of character and she started whining and complaining about how hard everything was. i guess my intensity went too far because the next day when we talked about it, she was upset that i didn't respect her boundaries or understand what this play meant to her. i felt bad but also kinda confused bc honestly i thought playing the role of a strict coach was part of the deal. now we're still together and figuring out how to do this stuff better without stepping on each other's toes too much. i dunno if i'm being the asshole here or not, she said it wasn't my fault but more that she needs to be clearer with me about what kind of play makes her comfortable. anyway just thought i'd share our experience cuz we've both learned a lot from this and wanna help others understand there's no shame in trying something new together as long as everyone's happy and safe.