Mmmm, dom!Regulus is a lot yummier than I'd have imagined!

I really liked the line "Draco didn’t even get the chance to consider whether he should ask why this time, since the boy promptly answered the question with a practical demonstration." I don't know why that one stuck in my head, but... there it is.

Incest and dun!con are tough subject matter, but you've managed to make them believable and hot at the same time. Well done!