A penis that is large and cannot be taken everyday without pain, it is called a vacation dick because its too large for a daily basis and therefore on vacation or weekends. It is not always on vacation but it a penis too large to have on a daily basis for the average female or male. You normally see vacation dicks on porn
(1) Associated with a really good fling or a good "side dick/bitch"
(2) Used as a general to describe a good sex session.
(Simply put: some very good dick)