Well I have read everyone's suggestions and taylored them to me.
First off I have a nice long discussion with my son about skipping and how that now impacts his grades. Because the 2 instances he has skipped are unexcused it cuts his grade down significantly. His problem. Not mine.
I told him that I would be talking to him and his gf about the no gf at my house rule when we aren't home. I said I had no problem sitting down with both of them and embarrassing the heck out of them with the next topic...the dreaded sex talk

. I actually entertained the idea of making them both carry around baby dolls for a few days whenever they were at my house and changing baby doll diapers, etc... That was just for giggles though!

More funny than helpful probably.
I said he had to get a job by graduation in May. That one is hard since where we live in Michigan is a challenge but it's out there. If he doesn't get hired somewhere I will have to come up with something next.
I also told him it was time to start taking responsiblilty for himself. No more hand holding from me on what he is supposed to do. He needs to figure some stuff out for himself if he wants to grow up.
Thats where I am at so far.
Thanks for all the comments!