I suppose it depends on what you mean by share. I've worked with a second dom on my sub more than once. I've never loaned her out to another dom. Once I did have her service another dom with her mouth. It was interesting to watch her from a different POV. Having her whipped while sucking me was quite nice. My sub really wanted to give up control. So after I collared her we tossed safe words out. She found not having a say in how much suffering she had to endure when I was feeling sadistic a great turn on. We were together for five years after she gave up her safe word, and would probably still be together except for the fact we were both married. Damn. I miss her.