What about all those so called Muslims who are Muslims just for the name, if marrying a gora who belives in Allah is zina then marrying all those so called muslims should be zina too.
if the "so-called" muslim isn't practising, yet STILL believes in the shahada, then he is sitll a Muslim, marriage to him would in no way put it at par with zina.
Secondly, if he hides from a girl his true feelings (or lack of) for the religion of Islam then its not the girl's fault is it? she's not to blame of zina or whatever bcoz of her ignorance to the truth.