Although this is perhaps the most difficult topic for both parents and kids to talk to each other about, you do have a responsibility to let him know your values connected with sex/sexuality and to provide him with accurate information about disease prevention and birth control. Having "major event" discussions about these subjects is not the route to take. You can take advantage of natural opportunities (newspaper stories, TV and movie content, anecdotes, etc.) to let him know your thoughts, feelings and values regarding sexual matters; these comments can be brief and not condescending. He will come to know the information he needs and your values concerning sex, in spite of himself. You see he is duty-bound to play the role of the independent, aloof teenager, whether or not he's comfortable or not with this role.
He's at an age and stage of hormonal explosion and confusion as to what to do with all these powerful sexual feelings. His anger towards you is in direct proportion to the intensity of that explosion and confusion. Try my less confrontative but active approach in this area; show rather than preach how your family embraces sexuality as a healthy part of being human. And fully expect to be told to get off his case. If all that takes place then you and he are doing the best you can in this thorny but very important developmental area.