Dear Elsa,
I hope this letter finds you well. I haven't heard back from you in more than a fortnight, and I think I've become so conditioned by your letters arriving every ten to fourteen days that I find myself writing another letter to you on this fourteenth night. I will wait another few days before I send this off, but it seems I can't help myself in writing it.
If my last letter struck you as offensive or untoward, I apologize. That was not my intention. I didn't mean to hint at or suggest anything more than what I felt.
If you want to discontinue this correspondence, the only thing I ask of you is to give me some semblance of warning before you stop entirely.
Yours,
Hans