I think the whole jealousy thing only relates to you at the moment.
I went round to the Pancakes house with a sim, seduced Bob right in front of Eliza. No problems. Called them all into the bedroom and gave Bob a serious woohooing with Eliza right there. She just left the room. Nothing.
But, when I went downstairs and seduced Eliza, Bob hit the roof; sad, jealous, the whole box and dice, but at ME! Left me wondering what they do when no one is around....
I bet anything that's because Bob and Eliza's relationship is not good at the start of the game.
