Wow are u serious? .. Beside as far as my knowledge is even if he is ale-kitab muslim girls are not allowed to marry outside Islam.. no?
It's up for debate. The think the Quran says believing women should marry believing men and nonbelieving women should marry nonbelieving men. It also says not to marry your daughters to people who commit shirk.
It's patriarchal society that has gone on to say that men can marry Christians and Jews, but women cannot. Either way, I feel it is always better to marry a Muslim, but I don't know that it is better to live alone and unhappy if you find a good moral person with whom you can make a happy home, who happens not to have embraced Islam (yet).