"I'm not speaking in code" is fairly clear. "I'm not saying anything that needs to be deciphered or reinterpreted; I'm saying exactly what I mean." I checked up on the other quote. "Cake and watermelon" is used figuratively to mean an (innocent) enticement. "Come to our party! We have cake! We have watermelon!" Something that would initially attract people to the website, I guess.

1. I'm not speaking in code = I mean exactly what I am saying. 2. I guess they must have been eating cake and watermelon or something.