For boys: Either go bowling, have a baseball party, or go swimming.
nothing, let them wear what they want.
T-shirt and Pant
NO
yes if you want to
Not all teenage boys cross dress. But, curiosity is the usual reason.
Swimming because it's more fun to it than sport.
It all depends on what they are going to do in the pool. If it is just recreational swimming the just swim trunks. If you are actually swimming competitively, the maybe jammers or a speedo.
something like "boy shes cute"
i am an eight year old boy and i only wear pants to school.
Most 15 year-old boys are fertile.
You should make a list of the pros and cons, plus why you want to wear girls underwear. As a 12 year old boy, you will need to make your mom understand why you do not want to wear boys underwear.