The product of the belief in a certain urban legend: that having sex in a hot tub makes it impossible for you to become pregnant.
If an individual is unintelligent enough to believe this, they deserve to be unexpectedly pregnant. However, this just means that the population of stupidity will grow, due to stupid people having tons of babies.
It is supposed that a child stemming from this type of conception will be born to ridiculous parents and grow up to be completely lame itself.
1. "What a stupid thing to say! You are such a hot tub baby!"
2. "omg, typos galore, I feel like such a hot tub baby."