Do we really have to address something this patently dangerous. Sir, would you stick your fingers in an electrical socket? If your wife wants to have sex with other men, she is welcome to do so, after the divorce.
She wants to make you a cuckold. What is her motivation? Some men want to be, and find it exciting - I don't really understand why this is, but it is certainly a thing. Look beyond the idea of the initial event (you sound like you are interested in the idea), and think about how this will affect you and your relationship afterwards, and long term.