Hi joslin.... I know exactly how you feel! I'm 22 and I have a 17 year old brother who has been sexually active with his g/f. We just found out, but we believe it could've been as long as 2 years. (Same girl.) They actually resorted to stealing my birth control pills when I was still living at home. (That's why I got pregnant 1 month after my wedding.. lol.) My mom has been worried sick, but it's been nearly impossible to control them since they sneak around. I don't know what to tell you, except I really do understand your concern. I think you have a good reason to be worried, and it shows how much you care about your brother. There is so much trouble with sex out there, and teenagers think they are old enough to deal with consequences and make "mature, responsible decisions" because they read that in teen mags and hear it from sex ed teachers. But I'm not that far removed from my teenage years, and I realize that just a few years ago, I didn't have a clue what maturity or responsibility was. Have you tried talking to him? My brother seems to listen to and respect me more than my mother right now, because he resents her for trying to curb his sex life. I just had a sit down with him and told him from my heart how I felt and what I'd learned. Did he listen? Not sure. But he seems to be behaving with a little more class than he was before.