In the movie series, Jedi's are sworn to fight for peace and order. It's believed strong emotional attachments lead to the dark side.
Colin, 7, wrote Lucas in hopes to change the rule and he wrote back, "To be a Jedi is to truly know the value of friendship of compassion and loyalty and these values are important in a marriage."
"Oh my God, I can get married? No way! George Lucas is so nice," Colin said.
Lucas also sent Colin "Star Wars" swag for the Jedi in training and signed-off with "may the force be with you."