Here's a little weird question that i never asked anyone because I assume its general knowledge. Say a guy is boning a girl condomless and he generates a lot of pre cum. So while he is doing her, the precum is in side it but it won't let her get pregnant? So he pulls out and shoots on her and everything is ok. However, you get these stories where someone pops a lil bobby pin into a condom, and the guy gets this chick pregnant? Basically, my question is how much semen is required to make a baby? and far 'in' do you have to be?