Do you know FIL was doing just prior to his? Was he talking to you, hubby, one of the kids, or the dog? Was he petting Rocky? Or waving his hands around as he talked? Was he standing or sitting? Has FIL visited prior to this, or is this the first time Rocky met him? Did FIL have food on a plate?

Some of this will help get an idea of what is going on with Rocky. With more info, folks will be able to give you more guidance.