Potty blues

So, as I have mentioned before, we are trying to potty train my youngest son and have even offered up a hefty reward, trip to Disney World, with no luck. However, when I picked my 5 year old kindergartener up school, I was informed that he had an accident at school and wet his pants. Now, I wouldn’t normally be concerned, accidents happen. But, this is the 3rd time he has had an accident at school in the 3 months of school! He has been fully potty trained for a few years now and never has accidents at home. Really. What is up with my children not wanting to use the bathroom!!! I have no idea how to stop it or him! We have had a talk and hoping that helps. But, geez, these potty issues are getting crazy!!!