M.K.
A real test of patience, isn't it? We're going thru the same thing with our three year old son and there's not a new baby around. Seems that he's just being stubborn or took on the 'been there-done that' attitude. It was suggested to us to let him make the decision to either wear underwear or pull-ups (some toddlers want the opportunity to make the decision themselves since they may feel like they're always being told what to do) but we just stick to what we've been doing... rewarding him w/ small surprises when his potty chart is full of stickers and praising him all the way. Recently we've been having him help clean up himself and the mess to teach him personal accountability. Seems to be working a bit... hopefully he'll get tired of fetching clean clothes and being part of the clean-up crew :) I'm going to keep watch and see what other moms suggest too!