If you don't want to move to Leeds, then don't. But make it be about you, and not because you are unsure of the relationship.
What is your objection to trying a long distance relationship with him for a while? Or visiting each other? Or anything like that? I know you want to settle down, but you just graduated from university and are looking for work yourself. Why not take a little time, both of you get your lives/careers/etc in order and then see where you want to take things?
Good luck.
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