Oh yeah, there are definitely some giggle-worthy lines/moments in here. Not least of which is "Look, I'm not gay" being followed up with "Your cock feels so good." (And really, I think that's a tiny bit of meta about the condition of at least 50% of all first-time slash fic, hah!)
Nice job with the sex that's hilariously unsexy. And yeah, I really, really imagine these two totally would talk and bicker and boss each other all the way though the event.
Love the irony of Goyle having a vastly intelligent and deeply, er, idiosyncratic Ravenclaw for a son. Heh.