Alright, so I created a sim to be a 'test subject' for relationships. I thought to make a fire on my lot and seduce a fire fighter. Well, as soon as the fire started... 8 different sims came running to the fire. One of them caught on fire, as did a teenager. Another was scared so badly, he fainted. Everyone was freaking out, so I thought now would be a good time to call that fire fighter.
Luckily... VERY luckily, it was a girl. She put out the people on fire and the stove, so after everyone left, I called her. She came over and I bought a bed, after a few Romantic Interactions. etc. etc. I built a dream cottage for them... About 1 sim hour later, she's pregnant. So, I'm still toying around with these two, hoping for the baby to arrive. Anyone can wish me luck it's not triplets.