Two and a Half Men - Season 1 Episode 24 -

Charlie is sure he isn't ready for fatherhood after a year of trying to raise Jake, so he opts to have a vasectomy. But when the doctor performing the procedure keeps getting calls from his wife -- who's about to give birth -- Charlie starts to think about what fatherhood might entail and likes the idea, provided he still has his vital organs intact (in more ways than one).