Pants or Shorts?

This morning I grabbed a pair of "underwear" for Reece.  When he put them on, he said that they were a little tight but I didn't think much of it.  Later in the day he was changing into different pants.  I noticed that the "underwear" that I had given him were actually a pair of Carson's size 3 month pants!  How in the heck did my 5 year old get those on...no wonder he said they were tight!