Staying Power in Chastity - The RO and Keyholder Education

My KH commented that we need to address my reduced ability to handle PIV sex for extended periods. Before entering chastity, I was frequently masturbating and had a much better capacity to go at it vigorously and bring her to orgasm during PIV. Now that I am only permitted to ejaculate with her permission, I reach the peak of pleasure quite quickly and lack the control to go hard and fast as I did previously. Obviously ruined orgasms are an option, but I have brought them up to her a few times. We experienced one somewhat by accident during PIV when I pulled out trying to hold back since I didn’t have permission to cum. I would like input on how other couples and key holders approach this seemingly common issue. Perhaps the best ways to teach her about the RO and methods I can use to give her the pleasure she seeks with PIV sex involving her cock, without the side effects of letting me experience a full orgasm. Do most people find they can maintain an erection right after an RO? I have told her that I’ve visited this forum here. I haven’t pushed her to lurk or join; I am perhaps a bit intimidated by what that might bring even though I don’t think she would be prone to joining the board. I also are aware of some KH books, but have not bought one for her yet. Advice welcome.