Marshall: Ted, how would you handle "the talk"?
Ted: Well, Marvin would be a young adult, so you wouldn't want to talk down to him. But that doesn't mean you can't get down with him.
[fantasy of Ted using a puppet to rap to fourteen-year-old Marvin:]
Ted: When two adults wish to procreate They lay together and copulate Male gametes, spermatozoa Implant themselves in the ladies' ova! Break it down!
[reality:]
Barney: I'm sorry, don't you need to actually have had sex in order to explain it?
Ted: Professor Infosaurus also has a rap about ignoring bullies.