communities in the way of development

Holy un-polly poll, Batman! No, but a question: Could you imagine being in a serious long-term exclusive (etc. etc.) relationship, all other factors allowing, with someone who didn't know (and didn't learn to know) your (whatever you consider your primary) language? Assuming that you were able to communicate, that is - that you, then, spoke their primary language (as a foreign language of some degree) and/or that you two had some third language, foreign to both of you, in common.

(Are you in such a relationship? Have you been? How does/did that work out for you?)

Bonus round: to what extent does your answer depend on what language we're assuming your immediate living environment would use in this scenario?

Bonus round two: Conversely, could you be/are you/have you been in a serious-type relationship where the other person's primary language would be/is/was one you didn't know, and not learn it, if they were/are able to speak yours and/or you used/use some third language to communicate?

(If you like, I could totally draw up a nice picture of poll results by hand. Also, I'm nearly sure it would be a deal-breaker for me personally.)

Going home again, to work, for the weekend. O bliss indeed.

[Edited somewhat because I'm unable to communicate in English.]