How to let my partner know I want more intensity and duration during our sessions

Hello everyone, My partner and I have had a few sessions that went really well. She is the Domme, and I am her submissive. While she hasn’t always been deeply into it, she seems to be getting more involved as time goes on. I know better than to rush her; letting her take things slowly prevents stress and avoids applying too much pressure.

I want to let her know that I can handle a stronger whip strike or similar intensity, but how do I communicate this without seeming critical? Right now, our sessions are quite brief because we usually have sex during them, which is wonderful. However, it often ends right after intercourse would be lovely if the scene continued afterward, though I expect that will develop naturally over time.

Any advice you can offer would be greatly appreciated.

Many thanks.