Give it time. I don't think he can really understand anything much about love at age 17 after only going out with her for a month. Stuart_G makes an excellent point too - hiding information from each other is not an indication of a healthy relationship. I think the key here is not to do anything too rash - it'll hurt. He needs to take a good long time to really think about what he thinks love is and about how he thinks this relationship could affect his life. I'm not saying it's not possible for it to work out, thousands of years ago couples started ahving children in their teens, but in today's society he has to consider other things such as further education and work. For all those people who'd say they'd leg it, that's easy to tell another guy, but what would you do if you current partner revealed similar information to you? Don't say it's not possible, just be hypothetical here. Regardless, I think leaving the relationship would be the best thing to do.