I know there are many arguments both for and against kids in F. We have all read many threads on this topic. I have my opinions as well. However, whether we agree with it or disagree, I wanted to see the general reaction to this incident:
Sun FLT 99 PHL -> DEN. Mom and Dad are sitting with Junior Lap Child (18 months old) in F. Although I am not a fan of kids in F, Junior was actually well-bahaved for the whole flight. No problems at all until Dad decided he was going to change Junior's diaper right there in the seat!
From my vantage point, I could both see and SMELL everything that was going on

.
Needless to say, I was floored. I understand aircraft bathrooms are not the most convenient places...but there is a reason they are equipped with a changing table. The FA was standing in the doorway of the galley and we actually caught each others eye and all I could say was "nasty" outloud. She just shook her head.
I had my noise cancelling headphones on, so I probably said it a little louder than necessary. Mom gave the half-turn and rolled her eyes at me. You are going to roll your eyes at me?
I don't think this appropriate in any class of service. Perhaps this incident just fuels my dislike of kids in F, but this one just clearly showed the lack of class by the parents.
For the pro-kids in F folks, flame on. I am a big boy and I can handle it. ^