I need a older guy to fuck my wife

Hi all, we are a couple from uk an my wife is 23 years old.
I would like to find a mature man 40+ to help me take my wife to the point of having sex with other men.
Many times when we have sex we use a big vibrator and I tell her that I like to see her with another dick, but I think she takes everything as a joke and I don't know exactly how to convince her.
What I know for sure is that 2 weeks ago she cheated on me with her boss. But she doesn't know that I know.
I'm very serious about that.
Love to help am 69 from uk