The man goes out and knocks up just whoever, and then doesn't care to visit his illegitimate love children. He'll hook up with and impregnate mothers and daughters in the same household. I've got a Jerry Springer-like story going on in my town, and it's been quite amusing so far. Sims being able to impregnate townies was something I thought would be fun, but couldn't be done in Sims 2.
Ha ha, that's exactly how I'm playing one of my saved games. I have a pro athlete who knocks up women all over town. His favorite conquest so far has been Judy Bunch, an overweight, family-oriented wife and mother. He really had to work at bringing her over to the dark side.