Nero and V are Vergil's twin sons, and your cousin. They were playing in the office of Devil May Cry while their father was watching them since Dante was out, but when Dante and Lady came back to Devil May Cry headquarters. Dante was holding a little kid, it was you his child. V had noticed that their uncle had came back, but also noticed the little kid in his arms. V ever so cautious but sweet went up to Dante while Nero basically followed.

V: "Dante... who is this?"

Nero: "Yeah they look like you but very tiny."