[Kartoffel]

My 16 year old son has been very secretive lately and hasn't been talking to me and my wife much. I always had a suspicion that something was going on until I walked into his room one day and I saw a magazine full of naked guys. Obviously his girlfriend that he didn't tell us about is coming over to our house and bringing magazines full of naked guys into his room. I'm worried that he might get her pregnant. How is the best way to give the birds and the bees talk?