Bless your heart, tc, that's pretty awful. Boys will be boys . . . I have one of those too. He's done some pretty awful things, but he never took a whizz in front of the whole congregation . . . ONLY because he never thought of it (or never needed to "go" while in church. We always made a stop at the restrooms on the way in, because when the kids were really small they would announce their bodily needs very loudly and very specifically as to exactly what they needed to do . . . )
Tom is one of my "autism-spectrum" boys - i.e., the really weird ones - and using the bathroom was a difficult concept for him. At least he never got the idea that he was a Greek hermit, like Pat. "I'm not going to eat supper, thank you. That is chicken. We will eat dry bread."
The first time I let my then 3-yr old daughter dress herself for church, she did a lovely job, putting on the right dress, the right shoes, etc. It was only when she stood on the kneeler and leaned over the pew in front of her, and I heard a wave of giggles break out behind me, that I realized the one thing she had neglected was anything under the dress.
This one is from a friend of mine from college whose brother married a Catholic girl and joined the church. They had two young children, a boy and a girl, and moved to Chicago. It was Christmas soon after they got there, and they hadn't settled in a parish yet, so they decided to go to Christmas Eve Mass at the Cathedral, along with the wife's parents, who were visiting from San Antonio.
He called the Cathedral to get directions, and the secretary said they needed tickets for the Mass. Free tickets. So he ordered the right number of tickets and got the directions, and off they went to Mass, with plenty of lead time to get lost. It turned out the reason they needed tickets was that the Papal Legate was there ("some Cardinal from Rome," according to my Baptist friend :-), and the Mass was being televised live on local stations.
When the family got there - Mom and Dad, grandparents, two cute kids, all dressed up - the usher decided to put them right up front. All goes well until the entrance procession, with the Legate, the Archbishop, the vicar, etc., etc., ... AND the incense! Their little girl hollered out, "YUCK! UGH! That stinks! I want to leave now!" and then the little boy says, "I have to go the bathroom NOW!" and grabbed his bottom and started leaping wildly, with significant gestures. And the cameras are pointed right at them ...
And it was on live TV in Chicago.
Funny you should mention that. Just today, that very thing happened during Mass. I expect my almost four year old to make it through without using the bathroom. Almost two year old knows she if she starts to pull down her tights, I'll run her out.
Anyway, today, elder daughter announces she need to go potty. I tell her she needs to wait until after mass. She wails (rather loudly) "But I don't want to go pee pee in my panties."
So I took her out. I did remember that in the rush this morning, I didn't make her go and her pullup was dry, so she did really need to go. Chalk this one up to bad parenting.