!!!!!!!!!!!WARNING TO ALL MEN!!!!!!!!!!
Don't use a laptop on your lap especially ones that get really hot like a MBP. It can do extensive damage to any future children you wish to create.
And I'm not kidding around either!
Well, I've got mine on my lap at the moment, and the only warm part is way, way down lower than that particular sensitive area, closer to my knees. I could see this being a problem if you laid down on your back, had the laptop on your belly with the hot end right there...well, you know where...