text: Missions don't last forever. Young men typically serve a 2-year mission between the ages of 19-21.\n Ask him where he's from and how mush time he has left on his mission. Above all: respect his current objective: Serving a mission in the name of Jesus Christ. Respect that and he'll very much appreciate it and respect you all the more. After his mission is complete he can date and/or marry whom ever he chooses.