Diaz, who is currently dating Alex 'A-Rod' Rodriguez, doesn't think her Bad Teacher co-star and ex-boyfriend, Timberlake, 30, is a geek.
She said: 'He's great at making fun of himself, but if you're really a true nerd, you can't really make fun of yourself that way, you have to be aware of it.
'He's a bad boy.'
The 38-year-old, who plays a foul mouthed teacher called Elizabeth Halsey in the new flick, admits she would teach 'dating' in school if she was a teacher because relationships are hard.
Speaking on BBC Radio 1, she added: 'I was terrible at school, I wasn't interested... Art and P.E. were my favourite after that I was like what do I need algebra for.
'In school there's a lot of things that you spend a lot of time learning that you never actually use in life... So I would like to teach something that's more practical in the real world.
'Dating... Why not? How to have relationships, it's very difficult!'