The play bow
Most people know that when a dog stomps down into a bow position it means that the dog is inviting play. Yesterday Tilley was play bowing to Luke; but that is as far as it went. In an excited state; perhaps wound up by Luke's whirling dervish behavior she invited play. When Luke responded with a play bow this went on for about 5 minutes, just bowing. Once it was clear that Tilley was up for play Luke proceeded where he was abruptly halted. Tilley put on her "face" and sat down ignoring Luke; giving off clear "get lost" signals.
So the initial bow does invite an interaction but like humans they can change their mind. While invited to play; Tilley knows that she is not stable on her feet anymore, surely not stable enough to withstand Luke's body slams. So although she wanted to play; her body said no. This can happen between any two dogs or dog and human; dogs play bow to us as well. But depending on the interaction between the two participants things can change quickly.
I have often seen an invitation to play; the other dog accepts and they start to romp. No sooner does the romping start; it is quickly ended with some serious growls and body language. So the canine guardians are left scratching their heads; what they heck just happened? IF you were watching very closely you would have seen; someone over stepped their boundaries or did something the other didn't appreciate. Thus the game is over; that's it, that's all. No grudges; the dogs simply move on.
So; as clear as a play bow is an invitation to play, proceeding body language must be watched to see how the play, is playing out.