How is Nero in Devil May Cry 4 related to Dante?

No Nero is Dantes nephew and is Vergils son....Dante has a son but it doesnt mention his name. YouTube.com/watch?v=lvpKRqdVXRg&NR=1">http://www.YouTube.com/watch?v=lvpKRqdVXRg&NR=1 heres the link and at 8:26 in the vid it refers to Dantes son