Didn't see it coming!

I would like to think I will never forget what I witnessed on Wednesday afternoon, but given my horrible memory, I have to make an entry. The girls and I were at the park with my friend Brook and her two kids. The girls and I were playing hide-n-seek and it was my turn to be the seeker. I spotted Ashlyn & Kylie first, who were hiding together. I then proceeded to look for Makenzie, when Kylie spots her first and yells, "Makenzie has her pants down!" I turn the corner and spot my oldest urinating on the people's lawn that sits just a couple of yards from the park. My first reaction was "What are you doing? (like it wasn't obvious, but what else was I going to say?) and then I quickly walked away as if she wasn't my child! This was a BAD idea!! Afterall, what else do little sisters do when they see their big sisters doing something? Yep, they copy them. Within seconds, Ashlyn drops her shorts, rips off her diaper, and starts running around. I think Brook was laughing so hard she was crying, but secretly I know she was thinking to herself, "Are those McGilvray kids raised in a barn?" Now granted, there have been a couple of instances in the past few months where Makenzie had to use the restroom and we were nowhere near one. Our only option at those two times were to have her squat and go to the bathroom in the grass. But by no means is this a regular occasion. Not even on our last camping trip did we face this circumstance because we brought our travel potty with us.
I am still not sure why Makenzie acted so impulsively, but then again, she is four, and sometimes doesn't give too much thought before reacting. It's not like she told me several time that she needed to go to the bathroom and I ignored her. Nope, she never once mentioned that she needed to go.
Needless to say, we had a discussion at dinner about when it is appropriate to squat and when it is not. Someone's lawn that sits just a few steps away from a public park is definitely not the place to drop your pants and let it all out!