One of the things on the side is a small indoor soccer field. As we were getting ready to leave, Aaron asked for a few minutes to play soccer, so I said o.k.
After a few minutes, I saw that there was a father of an approximately same age boy as Aaron on the field, stealing the ball from other kids (particularly Aaron, who is aggressive about getting it) and passing it to his son so his son.
To say this annoyed me is to understate matters. So I went on to the field and used my considerable bulk and vestigial soccer skills to block this annoying father in a corner, steal the ball from him, and pass it to Aaron.
Apparently, this had the necessary effect as Annoying Dad was content to cheer from the sideline for the few minutes we remained before I told Aaron it was time to go.
This sort of thing really infruiates me. I'm all for helping your kid and so forth, but not at the expense of other children. And, bluntly, you do not mess with my kid while I am around. I have a very low threshold for that and I am not shy about corrective action.
While I suppose I am glad it ended peaceably, I was quite sorry I did not get a chance to wipe the floor with Annoying Dad. Indeed, I suspect I was more upset about it than Aaron was.