learned behavior

Yesterday evening I am at cheerleading practice with the 6 year old girls.  (I also have the 2 year old boys with me, and my 9 year old son. My 9 year old daughter is at soccer with my husband coaching).  We've been working on potty training for weeks now.  My boys are completely trained, and can do it perfectly, no problem---provided they are naked.  The minute any type of clothing, pull up underwear, etc is on their bodies they forget everything they've learned. (This goes over well at preschool).  So last night, we are at the playground, watching practice when Collin announces his "Pee pee is coming out RIGHT NOW".  I realize we will never make it all the way up the hill, into the school, down the hall, and into the bathroom.  And I want to reinforce this potty training  breakthrough, rather than letting him pee the pull up.   So I really quickly hustle him around the corner, and behind a parked car.  Sadly, he suffers a bit of performance anxiety, and it takes a bit longer to get the job done than I had anticipated.   As I am helping him readjust his "Bun Bob Pear Pants" shorts, I turn around and realize there are 2 little tots who have followed us to our hiding place.  Two kids  who now have their pants down and are peeing in the grass.  Their parents will be so pleased when they show off this new trick they learned.