Hi Sadieblue
Ahhh that's not a fun spot to be in.
What are the bosses instructions? Does he say I do not wish to be disturbed? If yes,
then why does he have you call him, while the visitors are there?
If it's office policy that he wants you to call him - You could say the following:
Mr. Boss Who does not wish to be Disturbed ; )
I do know that you informed me you are tied up all day. However, Mr. So and So has stopped in the office to see you and I know you would want to know . Is there a time that I can schedule for Mr. So and So to come back that would be convenient for you?
I bet whatever you are doing is fine. But check with Mr. Boss person first - but if he's too grumpy to ask, then try what I suggested above.
Just remember how awful a this makes you feel....when your the boss
Hang in there.