I wonder if this is a language issue. I’m sorry, I don’t really understand the question.
But religion is like a penis. When you are in public or meeting new people you just really need to keep it in your pants.

I don't understand the question. "We" in this context would be the members of this site who overwhelmingly ARE unbelievers. Why would it be a pressing question to us how we could have unbelieving friends or lovers? The opposite is the question that's usually asked, "can I get along with believers"? And that's mostly a question because believers have a nasty habit of thinking their beliefs should apply to everyone, not just to themselves.

Pretty simple...keep religion and your beliefs a personal choice not a right/wrong thing.
The world and people are a lot easier to understand when you accept your beliefs are yours...not universal truths

As most people on this site are unbelievers/nonbelievers you may need to restate your question.

Personally, I don't see what belief has to do with a love affair. An affair and a commitment are two very different things.

You’re going to have to clarify your questions.