tricks don´t work and would only cause trouble. My man started by asking me about my previous sex life, the telling of some of those experiences turned us both on. My mind started to think about it and we fantasized about it when having sex. In the end I thought why not. It might or might not work for you.
You really don't want to coerce or trick your wife into something that she isn't comfortable doing. Unless your marriage isn't important.
you could always tell her you had sex with her best friend/sister/mother/father that may make her want to get back at you and do it as well.
You need to treasure your wife more and stop wanting another man to touch her. Your making a big mistake.
Explain to her why you want it. She may feel threatened that once she does it, then you'll want to do it with other woman. Set the ground rules and let her know it will only be her indulging, or both of you, etc. She may be afraid your gay, etc. Communicate!
good answer from biondetta
tell her to think of the other guy as a sex toy that you both are using for pleasure. He really is not a lover. he ismore of a prop for you to use for your sexual fantasy.