Can a modern young witch and a mortal boy find happiness in marriage?
Of course they can. If the witch is of the immortal brand of witch and the boy is mortal, they have happiness in marriage for five, ten, fifteen, maybe even twenty or thirty years. Eventually though, he grows old as she is forced to watch. Either the stress of that kills their relationship – he grows bitter that she doesn’t age, she hates watching him age – or she watches him die and it breaks her heart. The latter is the stuff great, tragic romance stories are made of. They seem happy at the ending, but only because they end with the marriage. It never considers that years later it all changes. If you want a great story about an immortal girl and a mortal boy, try reading Stardust by Neil Gaiman. The movie has an ending that is happier all around. The book has an ending closer to this question. (Plus, it’s a really great book.