As a parent with kids ranging from late teen to early 20's I thought I would throw in our parental perspective.
First of all, we wanted our kids to be educated about sex, so that they made informed decisions when the time came, whenever that was or will be. We talk to them about sex and we encourage them to come here (and other reputable places) to round out their knowledge, fill in the gaps and to maintain their privacy (it's ok that they don't want to tell us
everything).
Second, we wanted them to wait until they were mature enough to handle the responsibilities and potential consequences that come with the act - to quote from above.
Third,
whatever and whenever they decide, we wanted them to feel safe and secure in their environment (we would prefer the first time wasn't in the back of some car or down some alley-way, where they might not feel physically safe).
If our kids have sex, then they have sex - we can't stop that. We don't want the fact rubbing in our face, but we appreciate that they don't hide it from us and that we have a good enough communication that we can acknowledge it and be ok with it.
In a general way (not related to sex in this case - but still relevant), my eldest once said to me, "You treat me like a child". My reply was, "When you are 50 and I am 73, you will
still be my child. It has nothing to do with your age, it is about my love and concern for you as a parent, which will last my whole life."
Once she understood that being concerned and protective for her didn't mean I didn't respect her maturity and decision-making, it made a big difference to how she saw my input. That is (I hope) where your parents are coming from. Sometimes parents confuse caring for you, with making your decisions for you - realize that as a child grows up, it is as hard for the parent to adapt as it is for the child! You both have to be tolerent, open to communication and prepared to compromise to make it work.
We trust our kids to make the best decision they can, because they are informed and because they have shown themselves to be mature in other decisions they have made. It may not always be the decision we would have made for them - but hey, even parents can be wrong sometimes
. So far we have not been disappointed.