Boy (Harry) still needs a Green Card. Can't just waltz in as a foreigner with no job and become a resident, especially a European. Feds generally go through marriages like that with a fine tooth comb. Wife (US citizen) will have to insure support if he doesn't land a job.
This will be a textbook NBC situation, too, especially if they have a kid here. Exactly why the Founders wanted a NBC rule for the Presidency; To avoid foreign ascendancy to the office via arranged marriages.