Firstly, its indeed great to hear from you that you have realized your mistake. From your question it seems that you are indeed a dedicated daughter, who is loyal towards her parents. Partying with ur guy isn't a bad idea, but I know you are feeling guilty on the thought that you have lied to your parents. I think you should sit down with your mom and dad and tell them the truth. Its better to confess in an honest mode, rather than carrying the burden of guilt. They might be offended with you at the beginning, but at the same time they will be happy to see their daughter making a honest confession. Today's youth has the tendency to hide things from elders. But your thoughts are genuine. So tell them the truth. They will understand.