Well, in my opinion, there is nothing worse then a liar! Maybe the next time this woman calls, pick up another phone in another room, and listen in on their conversation, or insist that you go to the store with him. If he lets you come with him, and all it turns out to be is that he is looking for 'pro fisher' (LOL I have no idea what he likes) Then, I would ask him who that lady is. Is she a spokesman from 'pro fisher' that is calling him to say that 'pro fisher' is in a store near him? On the other hand, if he literally says, No, sorry, you can't come.... I would be mad.
Another idea is to say innocently enough to him, "Where's the magazine you bought?" If he won't show it to you, then I would get really suspicious, and just say cold turkey to him "Okay, what's going on"? (While he was out, pack you, Gwen, dogs things and call someone to give you a ride somewhere) If he doesn't tell you, just leave. Just say "Okay, I'm done. Goodbye" Take your daughter, your dogs and just walk out the front door, plain and simple. He'll be in too much shock to tell you whats going on.
-Laurr