It's hard to know what to say when the first thing a guest encounters, on entering your house, is a white packet in the hall, bearing the words "Inflatable cow pump".
A quizzical eyebrow, a tightening of the lips and a foot wedged firmly in the front door, to prevent its closing, convey her reaction clearly, without words: "You better have a good explanation, son."
As regular readers know, thinking fast is for me practically a superpower. But I take my time over this one. Rejecting my first thought - to lead the way upstairs and show her the inflatable cow standing perkily on the cabinet beside my bed - I decide on a full explanation of how the little chap got there in the first place.
"Why don't you come in, close the door and I'll tell you all about it?" I suggest.
"I'm fine here," she says.
"It's starting to rain."
"I like rain."
I sigh, take a seat on the bottom step of the stairway leading up from the hall, and cast my mind back to yesterday's expedition. "It began when Linda, my son's fiancée, sent us out to buy a bed for my grandson."
"You went out to buy a bed," my guest says, raising the other eyebrow. "And returned with an inflatable cow?"
"It seemed a good idea. My son thought so too. It was a joint decision."
"I haven't met your son. Is he a lot like you?
"Some say so."
"Does Linda have grey hair and a worried expression?"
"No, why would she?"
"Just a thought."
"Well, it wasn't only a cow. We also got a wee book, a hat with a fox's face on, and a plastic telephone with little wheels, so he could zoom around the floor with it."
"But no bed?" she says.
"No bed. The shop had a white one and a black one and we couldn't decide."
"Was Linda happy with your haul, when you got back?"
"Not happy, exactly. I wouldn't say happy. She wasn't jumping for joy."
"How would you describe her?"
"Tell you the truth I didn't see her. I'm only going by what my son told me later. By the time we got back to the flat he was looking kinda pensive. He said maybe I should go home and take the cow with me, as it might push Linda over the edge.
"I dunno what edge he meant. But I said I would and that's why it's in my house, where my grandson can play with it, any time he comes to visit."
My guest shakes her head. "It's a good story," she says. "It has the ring of truth to it. But I haven't been here before, so for all I know this inflatable cow is your best friend and you talk to her all the time."
"What if I do?" I say. "Writing is a tough job. Plenty of writers talk to inanimate objects. It helps us concentrate."
She pulls her collar up, takes her foot from the door and turns to leave. "I'm sure it does," she says. "I'm just worried that sometimes the cow talks back to you."
"Of course the cow doesn't talk back to me," I tell her. "That would be nuts."
She gets into her car and, just like that, she is gone. I wander through to the kitchen, make myself a cup of black coffee, climb the stairs to the bedroom, pat the cow on the head and say, "That didn't go well, old girl."
"Never mind, you've still got me," Ermintrude replies. "Would you like some milk in that coffee?"