I think author is just trying to say once you open your legs, you have taken the responsibility for your actions, and will have to continue to do so. Whether you are finding it hard making a choice or not. I know accidents do happen, and many of us felt invincible as a teenager, "oh well, I dont have a condom", "oh well I forgot my pill, it wont happen to me". "i will do what I want to do"
I myself do not believe in abortion, and I would never refrain from trying to get my point across when it comes to that, but I judge no man. I worry greatly of the impact of abortion on a teenager, for I know many a women have not recovered from the sense of loss and shame felt "after" the abortion. I mean I lost 6 baby's within a little over five years, and I only wish I could have them back. I never would have had an abortion, but I do know the sense of loss from losing many baby's.
God bless us all this day