My spouse has a friend who we both like a lot and love to hang out with her and her boyfriend, who is also very kind, but not as close as the friend. None of us have kids, we are all in our early 30s. We see each other as couples maybe once or twice per year, although we live in the same city. We've had some really enjoyable "couple dates", and I, being a regular guy with relatively good interpersonal skills, would say that this could become a good friendship. There is just one thing that strikes me as awkward and I don't know what it means and how to handle it:
Every time we meet and then say Good Bye, our befriended couple says, very sincerely, that we should hang out more often and that we should go on a vacation together. So far so good, my spouse and I would really like that. But when we inquire later on about a new date or specifically ask about going on a vacation, there are excuses such as "we are sick" (we've heard that one at least a dozen times), and no reply at all regarding the vacation.
It's important to note that all four participants have been born and raised in Germany. Germany has a very low-context and direct culture. Usually, when we say something, we mean it. It wouldn't strike me as awkward if the other couple was from an english-speaking culture, as this ritual appears to be more common there. There is, of course, a chance that one of them is really sick that often, but my statistical gut feeling tells me that this is unlikely. ;-)
How can I interpret their behaviour(s)? Is it just "being nice" and not really caring about us? How should we respond?
Edit for clarity: I would usually consider this as a nice way of saying "no", but there are other occurrences. For example, after we announced that we want to move to a city close by, we're being told, "No, please don't move away! We can't hang out anymore that easily!" -- This is not the usual "nice-no" one usually has to deal with. Why say something like that if there's no interest in hanging out anymore?