I'd say the hostile lasts as long as you guys haven't CF'ed. "topkds" can't make black on white rules and agreements what constitutes active hostiles or not -- it's always going to get abused then -- so rather ask yourself -- does this seem like a hostile and if your gut tells you yes, then it probably is. If this lasts 100hrs more without any form of diplo agreement and no other kds hitting in -- then yes, I'd still call it a hostile.

What's more interesting to discuss is how to try and make "deals" in the future where kingdoms somehow agree to give eachother relations somehow -- I'd prefer a mechanics change, but it should would help. I remember some deals that stated that neither kingdom could be fort and stuff. Shrug -- Let's just hope Bishop fixes relations