Being a strict follower of the man code, John had an aversion towards anything mushy. He had never said the L word to a person before (not even to his family) because the man code states that the L word should only be used by men when referring to food, gadgets or cars.
This was john’s first attempt at telling Ever that he was falling in love with her. He sent it to her as an anonymous message, using a new email account. Of course Ever knew right away who it was from. John wasn't exactly subtle in giving hints... and his nickname was still in the email address
Being the strict follower of the man code that he was and realizing that the letter was in violation of the man code, John tried to save his dignity by denying that the letter was from him
I realize that "eew" may not be the manliest of words but i think john was being sarcastic