Decades ago, my husband had watched me use a dildo on myself. Not only was it something that he enjoyed watching, it was a way for him to learn what took me over the edge. Using dildos while he watched was a positive.
I never thought about watching him until we started using the strapon and other toys on him. He said he was able to have hands free orgasms by using a dildo and giving himself anal/prostate stimulation. I tried to do it to him several times , but was never able to quite get him there. I suggested that he take a toy and show me exactly what he does, that takes him over the edge. Not only did it teach me what does it for him, I found it very exciting watching him do it to himself.
Have you shared learning experiences with your S/O?