Wife cheating spy recorder

My wife and I  have an open relationship , we have been together for 14 years , the last 5 years we decided to make it an open relation , so my wife now have a boyfriend for the last 2 years , I personally do not have any girlfriend and i prefer to stay open and have Casual sex .

Our open relation have 5 main rules , no one can break them :

  1. We stay happy married husband & wife
  2. Our sex life wont be affected by our open relation
  3. No 3 somes and the he/she we are dating or having sex with must think we are doing it behind the partner knowledge ( cheating )
  4. Me or my wife must tell when meeting bf/gf or have sex with another person
  5. No questions to be asked , and never fall in love with someone else

So  somehow it was a fun game for us and we are enjoying it , our marriage is perfect and our relation is amazing , but i always wonder how my wife and her boyfriend make love , i tried to convince her to invite him home and do it in the guest room while i leave the house , i was thinking to add a hidden cam , but this never worked , my wife did not want to mix our personal life with our open relation and getting some one to our house for her is not a good idea .

So one day i came up with the idea on spying on her with a spy recorder , i did some online search and found a smart key holder spy recorder which i bought and gave her as a present where she added to her car keys .

The day she told me she will meet with her boy friend i was so excited and at the same time worried that the spy recorder will not function as it should be , but i guess am lucky enough and the device worked in a perfect way .