Traveling (Pants) to Pittsburgh

I'm heading to Pittsburgh this weekend for a trip back to my childhood. On Saturday, I will be going to the Kennywood amusement park, and on Sunday, to the Pirates baseball game.

Since I mentioned it (sort of) above, I laugh every time I hear the title The Sisterhood of the Traveling Pants. I just picture pants floating from place to place. I feel like there will be traveling pants at a rest stop on the Pennsylvania Turnpike this weekend or possible getting gas or food in Breezewood, PA. Do the pants travel internationally or just stay within the United States? Here's the real question: do the Ya-Ya Sisterhood and Sisterhood of the Traveling Pants fight? Is there bitterness and distrust between the groups and a history of hatred between the two sisterhoods?