Sara,
How old is DD#1? Mine turns 3 in July right before our next baby's due and I dont' want 2 in diapers! We are potty training this week as well, and she doesn't want to go in the potty either, she would rather hold it... She can't do it forever though, right? Also, a tip for teaching your son time... Get an old clock you don't care about, and tape numbers all around with each number, so for the #1, you will put :05 right next to it, and on with the whole clock. That's what I did with my son, and he loved playing with the clock to learn the times.
Good luck!
Becky