Creepy? It happens! A fair bit! I can think of a few examples of sanctioned, approved animal/human (edit: both man and woman) marriages off the top of my head, and after investigating the personal story, presuming that the portrait of a slightly-adjusted but otherwise happy and stable domestic life was indeed correct, the only thing I can think "wrong" with it would be again the same debate we're having about semantics of what marriage actually entails.
That said, I am not sure how "valid" it would be because it wouldn't be difficult to believe that many animals would not really appreciate the "marriage" for what it is- that part is purely for human edification, really (human conventions, after all). But I contend that they wouldn't actually need to, so long as there was a discernible emotional bond between the two (which I also assert exists).
Anyway, like I said, will post another thread about it!