Explaining the Inside Joke

So, I thought I should explain the joke on me.

I'm telling the story to Sean about the horses that were loose yesterday and I said that we herded the horses. 
Sean - "You herded the horses? I'm pretty sure that isn't correct grammar, shouldn't you say you heard the horses and what did you hear by the way?"
haha, he's funny isn't he
So as I continue with my story the next time I say that the lady in the other car shooed the horses to the opening in the fence.
Sean - "She shooed the horses?  That's pretty impressive.  It's amazing that she had everything needed to shoe a horse in her car with her."
haha, funny again
I continue again and the next time I say that we were rounding up the horses.  As soon as it was out of my mouth, I knew what he was going to say.
Sean - "Round up, that isn't for horses it's for weeds."
I can't win.

If you have no idea what I'm talking about, read the post below