I think like you. I have known of another Dom who has done this, and they enjoyed themselves. The friend enjoyed having access to another's slave.
Like you, I would be in control of my slave, and what is done to her. Yes, I can see allowing her to be bound, tormented, and even whipped by the man I give her to. I would expect him being allowed to do anything to her I would do. I suppose the time might come when I would allow him the loan of her, by himself. Having said that, at first, I would always be there, and even participitating with him.
This is one of those subjects that you read about, but the actuallity is something that must be considered from all aspects. Thank you for your comments on what you did. Sounds like you enjoyed your decision, and would do it again.
JK