I'm having lunch then suddenly the dog barked.

I’m not twisting anything but I think more context is missing. You said you were having lunch but nothing indicates that your husband was also with you or eating too. No insight on the dynamics of your household and how lunch plays out for your relationship. The dog barked, typical when dogs hear something but was the dog inside or outside? If outside then it makes sense for your husband to excuse himself to check on the dog if he was eating with you. You say he’s outside talking with the lady dog groomer but again fail to add more details. Would you have been as peeved if it were a male dog groomer? Was the dog groomer at your door? Across the street? Next door? How long was he gone for? I agree he could have went to the door and said the dog groomer was there or nearby and he was going to talk to her but you were vague on the details. Was she a priority? Usually if there are guests coming to your home you greet them and don’t leave them hanging. Was she on duty or just someone from the neighborhood? You could have called, text or got up to check on your husband. The underlying issue I see is this could easily be fixed by having a simple conversation with your husband about this. Communication and boundaries are essential for a relationship. You’re not wrong there. Let your feelings be known to him in a rational way so he knows how you feel and what your expectations are if a similar situation were to happen. It’s good to worry and care for his safety. Or maybe you felt attention on you was neglected. But it’s him you need to express your feelings to.