How can I stop a sim from die-ing from laughter?

I try not to joke around to much with my sims because it gives them the mood that later leads to hysterics. I once tried for a baby at a nightclub with a sim I married right after, only to have him die from hysterics when they where married, so yeah I do feel they die a little easy from it. Did you do anything special that lead up to the hysterics before it happened? Telling jokes or something? Glad to hear you got her back eventually :)