Is being straightforward the best approach with a shy guy?

Is it better to just be straightforward and say, "Hey, do you want to go grab drinks/go to a movie?" Or do I need to leave some mystery so he chases me? I don't want him to lose interest.

We have gone out on 4 dates but I have had to initiate plans. We have kissed/made out. I usually text him first during the week. He is extremely shy and never had a girlfriend. He has told his friends about us too.

Shy guys: What is the best approach? I want to keep him interested without throwing myself at him 100%.
Is being straightforward the best approach with a shy guy?
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