Most gay men report that they knew they were gay between ages 9-11. Because of the social stigma with self identifying as gay, many young men tell themselves and others that they aren't gay. Also, some are bisexual, so they are genuinely interested in both males and females. It's great that your son can talk to you about his sexual attraction to others. How do you find out if he's gay? Ask him plainly if he thinks he's gay. Ask him if he has any attraction to girls. Ask him how strong his attraction is to girls and how it compares to his attraction to boys (ask him to rate it on a scale from 0-10). Ask him how he would feel if he is gay. Tell him you love him and will support him no matter what he is. Talk to him about safe sexual practices and the risks of not protecting himself (and not just about HIV/AIDS, but all STD's). It is okay, in my opinion, to tell him he's too young to act in sexual ways, just as you would if he was doing the same with a girl. Being gay is difficult enough in our society. If he thinks he's gay, it's important not to compound his problems by telling him he's not gay. There are web sites, such as http://www.siecus.org and http://www.pflag.org that can be helpful to you and your son. Good luck.