Awk-Ward!! Nice set up, though the kid would be more like 9, unless the reunion date is 10 months after the prom date, unless she’s rounding to make the moment even more awkward.
Many ways to write the guy’s part as a sequel.. he could follow her to the restroom and declare his undying love, or apologize and say goodbye. He could run away. He could take off and then stalk her and the boy later. He could send her an anonymous donation because he is so rich and successful and he wants her to shut up about his illegitmate son.. or just to be nice. Hmm.. many possibilities.

haha I totally forgot about that whole 9 month gestation thing. Did I mention I want to be a doctor? Yeah…

There are a lot of different options for a sequel. I think I may write a bunch of options. Since you’re brimming with ideas for one, you can have at it as well =)

i was going to, as I NEED to write a ficly, but I couldn’t decide what kind of guy he was.

Well… I’m not sure if I should poison your creativity with my comments, but I figured there has to be some reason she didn’t want to tell him originally. Whether or not he’s addressed this in any way is up to discretion!
But that’s just me – nothing is set in stone with this one!