Prince Achileas-Andreas of Greece just left his teens behind him — he turned 20 in August 2020. He is a member of the former Greek royal family, and is the second son and third child of Crown Prince Pavlos of Greece and Marie-Chantal Miller. His paternal grandparents were the last royals of Greece, until the monarchy's abolition in 1973. While Prince Achileas-Andreas might not be part of a functioning dynasty anymore, he is still enjoying life. He was born in New York City, grew up in…