In colloquial Chinese, the adjective two (or 2) can sometimes mean bad, vulgar, absurd or any form of inappropriate behaviour.
If one were to interpret this way, "too two" would mean extremely unacceptable behaviour. It is a derogatory term in the worst sense. The term is very powerful due to its rhyme and other verbal effects it creates, use with care to the Asian population.
He who thinks the world is "too simple, sometimes naive" is too two.