Possibly TwoJeffs' Casual Romance mod might help (depending on what it is you want). It has the option to set jealousy per person rather than per lot and it can be lot-wide or 'same room only', that sort of thing. From what I can see, NL uses the latter anyway, although possibly for woo-hoo it's lot-wide from what others have said. Certainly in my game flirting and so on isn't noticed unless it's the same room and it's not due to Casual Romance because I only use the jealousy aspect of it occasionally and haven't at all since NL (I like the fun too much).
The site with TwoJeffs' mods on is
http://www.variousimmers.net. I can't give a direct link as it's down at the moment.