Older Son (almost 10), while washing dishes: Mom, how do sperm come out of your body? Do they just come out when you pee?
Mom, trying to be nonchalant and still slightly abtruse: They come out when you ejaculate. You have to be sexually stimulated.
Son: So like when you have sex they come out and go "Wheeeee!"
Mom: Yeah, pretty much.
These next few years are going to be rough.