As for the rules themselves, I think that the rules we set for teenagers are a safety net, not a protective coating, the kids can get around them if they are determined.Set the rules that you think are appropriate for her, if they are not 100% enforceable acknowledge this to her, and be clear about the consequences if you do find out that they have been broken.When my daughter asked me when I thought a girl was ready to have sex, I replied ''when she's ready to handle a baby.'' We all know that every form of birth control has a failure rate, so I don't think it's too far out to talk about pregnancy.A lot of oral sex goes on in dating, with definite health risks, loss of reputation, etc. (There's a chance that he's a friend of a friend of a friend! My mother-bear self wants to lay down the law and tell her no way in hell is she going to be dating an 18 year old who we know nothing about.She needs to prove to you and herself that what you think, is of no concern to her - but it is a ruse - it matters more than she can accept or let on.
She is now 18, more mature and a fabulous person, looking back she says I was just a kid - what did I know that something like that would happen to me. I have a 16 year old daughter, though she is pretty easy, but I was a troubled 16 year old once (and I have also transracially adopted a child with challenges).Past efforts to monitor a dating situation have failed, either because of being lied to or because of being let down by a past boyfriend's dad who promised to supervise if the two spent time at his house when he WAS there and did not. Knowing I cannot control what she does, I want to set age- appropriate parameters and attempt to hold her to them. Also, these parameters cannot be based on expecting truthfulness or abstinence.They have to be based on something else, giving her reasonable guidelines within which to learn to take responsibility for herself.I guess that is what I would most emphasize: share with her your genuine concern that she make choices that support her and tell her that to that end you will set certain rules with certain consequences, but then acknowledge her responsibility for being the one who ultimately will make these decisions. PS - Alanon might be supportive for you as the parent, even if she is not using any substances, the issues are close enough.So I must ask first: What is it that you hope to accomplish with your rules?