Remember kids... always wear a helmet. (The almighty bikeradar helmet thread)

I need words of wisdom like that as a female.

Penis insults just aren't applicable. There's a severe lack of "reply back" insult parity ;)
Dick jokes work even better when spoken by a female.

Whynot combine them both.

"On your mum's dick"

With any luck, the buttnugget will be so confused as to fall of his bike and explode into a million tiny pieces.