I wasn't aware that was an option, but you could always go to the
SimPE forum and ask there. There were some hacks that did this, but they are no longer updated as far as I know, including Insim. However you could always use
Twojeffs ACR or
Pescado's romancemod. The ACR you have to set up for the neighbourhood, and includes a lot of other interactions that you need to be aware of before using it, so rftm. Pescado's romancemod simply makes adjustments to the jealousy reactions in order to make them more reasonable, but doesn't stop them completely.
Cheers