Hmmm... I've seen a bit of that but the complaint I've seen in this thread more often is that you don't have an option to tell her that your faith is personal and that you'd never let it damage your relationship. You can't say something along the lines of "I get that you are scared that my faith will tear us apart, but I promise you that it never will. I will always respect your right to believe differently to me." It seems like a false dichotomy of options just for the sake of drama - break up with her or agree with her statement that the elven gods are rubbish, and nothing in between is possible. You can of course read the scene as Sera knowing that you're lying but taking your lie as proof that she is more important than your faith, but that does a disservice to those who are RPing true lack of faith as I did...
I wish that you could discuss your doubts with her if you are roleplaying as an elf who doesn't really believe in elven gods. There is a line where you say that maybe it is true, but she just reacts like you are telling her that you believe it completely. I think there should have been some middle ground. Something to let her know that you wouldn't leave her or want her to be more 'elfy' would have been great.